Today is the 40th celebration of Earth Day. Back in 1970 when it started, the big issues were polluted air and poisoned water. Now, recycling and the size of your carbon footprint are what's important.

So instead of going green for just one day, a lot of us are adopting a more eco-friendly lifestyle overall. Now that doesn't mean running out and hugging trees, wearing Birkenstocks and foregoing deodorant... it means becoming more aware of what we use and what we buy. Wasting less. Saving more. And making sure we aren't contributing to early planet burnout.

Since a lot of us are permanently connected to our smart phones, a whole host of apps have been developed to make it easy being green. (Sorry, Kermit.) And our friends at CouponSherpa.com have put together a list of the top 50 that should be on every phone. After sorting through them, I grabbed a bunch of the ones I thought were the most important for guys, and listed them below. (If you want to see the full list of 50, click here.)

TRANSPORTATION

CarCare - $4.99
CarCare automatically calculates your gas mileage at the pump and reminds you when it's time to change the oil, rotate tires, get a wax or any other service you desire.

Carticipate - FREE
Hook up to a social network of folks who want to share rides. Just plug in your destination and Carticipate finds others in your social network headed in the same direction. You can hitch a ride or share your own vehicle.

GasBag - Basic version FREE, Pro version 99 cents
GasBag relies on a community of hundreds of thousands of users submitting prices across the U.S., U.K. and Australia, with price updates delivered to your phone in real-time. You also can track your car's mileage and record details of gas purchases.

Green Gas Saver - FREE
Green Gas Saver tells you when you're accelerating or taking a turn too fast, which can hinder your gas mileage. The idea behind the app is to keep the ball in the center of the screen. When you accelerate too quickly, the diameter of the ball increases and an alarm will sound, indicating you're accelerating too quickly. Green Gas also keeps a running score so you can see how well you're driving in real time. A few weeks with this app and driving efficiently will become ingrained.

Greenmeter - $5.99
Greenmeter by Cleantechnica tracks your car’s carbon footprint and fuel efficiency while calculating weather conditions, cost of fuel and vehicle weight. You also can measure drag coefficient, vehicle pitch and rolling resistance with estimates available at CleanTechnica.com.

iGasUp - $2.99
Tired of overpaying for gas or diesel? Get the cheapest price available every time you fill up with iGasUp. You'll gain access to the world's most accurate repository of U.S. retail for less than the price of a gallon of gas.

iTrans - $3.99
iTrans calculates the fastest route between stations and gives you a step-by-step guide. It even works when you're offline and underground. A search function, maps and advisories help make your commute less of a grind. Schedules include NYC, DC, NJT, CTA, Metra, PATH, LA Metro and Metrolink.

RepairPal - FREE
Whether it’s an auto emergency, a roadside breakdown or just a minor problem with your vehicle, RepairPal ensures you're prepared 24/7 for any emergency. RepairPal also provides accurate repair estimates; locates the nearest tow truck with one-touch roadside assistance; and helps you find the closest, quality repair shop.

Traffic - $1.99
Based on your current location, or any other location you configure, this app will retrieve the current traffic conditions and incidents in the area. Traffic then overlays them on a map or displays them in a customized listing. Each traffic item contains detailed information about the incident and can be plotted on the apps' map so you know exactly where the problem originates.

DINING OUT AND DINING IN

FoodMenus - 99 cents
FoodMenus is a searchable, location-based database of over 100,000 menus from restaurants across the U.S. that helps you make smart eating choices before you hit a restaurant or order take-out. You also can save your favorite menus for offline use and share them with friends.

Green Sushi Selector - 99 cents
Green Sushi Selector allows you to research whether the sushi fish you're about to buy comes from threatened species or has been caught or farmed in ways harmful to the environment. Fish are listed both by their Japanese and common-market names. Additional features include health alerts for mercury and PCBs, as well as dietary recommendations.

Seafood Watch - FREE
It's remarkable how little we know and are told about the seafood we eat. Seafood Watch, from the Monterey Bay Aquarium, is a searchable guide to the quality and origination point of seafood at grocery stores and restaurants.

VegOut - $2.99
Vegetarian offerings in many restaurants are often limited and boring. VegOut makes life a bit easier with the world's largest international listing of vegan, vegetarian and vegetarian-friendly restaurants. Search listings by your exact location or a customized location when on the road.

TRAVEL/OUTDOORS

iLocate - 99 cents
iLocate is a comprehensive searchable database of national and local parks, beaches, theme parks and amusement parks throughout the U.S. You'll find contact directions and details on each park.

Lonely Planet Travel Guides - Prices begin at 99 cents
Lonely Planet Travel Guides are the guide of choice for many frugal and green travelers. Various apps provide paperless guides for both U.S. and international destinations. Some of the guides are buggy and need work, but Lonely Planet is working on updated versions. Tip: Read the reviews before buying.

TrackMyTour - FREE
TrackMyTour is the social travel journal for those on the move. Whether biking, hiking, sailing or just traveling, this app allows you to keep your friends and family updated so they can share your adventures.

Trails - $2.99
The Trails GPS app allows you to record, import and export trails onto your iPhone. You can record maps while hiking, on bike trips or while jogging. Trails also allows you to geotag and geocode non-iPhone photos or share your track with others via Google Earth.

TrailBehind - 99 cents
Search for hikes, bike trails, campgrounds and other outdoor adventures. TrailBehind includes offline apps, geotagged photos and a filter to provide you with the information you need.

SHOPPING

FindGreen - FREE
Search more than 56,000 green and sustainable businesses to make everyday choices that will reduce your environmental impact. FindGreen finds everything from yoga centers (think flexible, healthy chicks), to bicycle shops to organic restaurants near you.

Harvest - Select the Best Produce- $1.99
Harvest helps you skip packaged and processed foods with information on selecting the freshest, ripest, healthiest and best-tasting produce. Now you can knock on watermelons, smell pineapples and squeeze avocados with knowledgeable élan.

Locavore - $2.99
Eat foods grown and raised locally without spending hours Googling data for tonight's meal. Locavore provides government and NGO data by state. Click on the food item for Wikipedia info and Epicurious recipes. There's no market-finder feature for in-season foods, but it sure beats printing lengthy lists of locally grown foods.

TheGoodGuide - FREE
GoodGuide helps you find safe, healthy and sustainable products while you shop. Simply scan the product's barcode to view detailed ratings for the health, environment and social responsibility of more than 65,000 products and companies.

MISCELLANEOUS

Discovery Channel - FREE
You’ll get daily news stories, quizzes, photos and TV schedules delivered directly to your iPhone. You also can watch your favorite shows, including Mythbusters, Shark Week, Man vs Wild and more. The Discovery Channel app will ignite your curiosity, immerse you in the how and why, and satisfy your craving for the latest information.

Get Green - 99 cents
Get Green, from Candied Apple, provides you with daily ammunition in the battle against climate change. You'll receive daily updates about how you can make a difference. Tips cover everything from green workplaces to green Halloween celebrations. It even has tips on how to reduce the carbon footprint of your wedding.

Green Charging - 99 cents
Green Changing reduces your energy consumption when you charge your phone. Launch the app when you start charging and it'll notify you with sound and vibration when your battery is fully charged. Some of the best things are so simple.

iGreen - 99 cents
Stay current on the latest solar, hybrid, green and green tech news. Aggregated new sites on iGreen include About My Planet, Azo CleanTech, VentureBeat, Green Biz, Green Computing, Hybrid Car Blog and more.

MeterRead - $2.99
Read your meter with ease using your iPhone. Check it again later and MeterRead provides you with data to better control your power bill. This app from Zerogate displays the total kilowatt hours used since the last reading and calculates your total usage for the next 30 days.