I run with a water bottle for any distance over 10 miles. It works out perfect especially in training runs where water fountains may be few and far in between. It also is helpful during events. As you can imagine, all those paper cups cannot be good for the environment. Running with a water bottle allows me to bypass the people slowing down to wait for a cup or grab it off the table. It's also easier to drink, since I can do it while I run without spilling all over myself (most times). Water stations at road races also typically have pitchers and volunteers are glad to fill up your water bottle if you ask nicely — a thank you afterwards is also always appreciated. It may take a few seconds to fill up the water bottle, but you've already passed several water stations where you didn't slow down, so you've banked a couple minutes to re-fill.
My recent poll on "the number of running shoes in your household" on facebook was very surprising. The average was around 7. Considering we are told that the miles are limited per shoe to drive us to buy more, our shoes can be very "ungreen." But if we use them properly, we can get longer use out of them. In my house, there are 4 pairs of running shoes. One is in heavy rotation, what I consider my "marathon" pair. These are the ones that carry the bulk of the miles and are used in longer runs and events. I have a second pair that has some "wear" on them, but are still usable. These can be used on mid mile runs and short runs. I also recently bought a "lighter" pair of shoes, that I save for 10ks and speed work. The final pair is an older version of the "lighter" shoes that are no longer used to run in. (I'm wearing them now) I use these for day to day things and have been retired from running, but can still be used daily. Overtime, the ones in heavy rotation will be bumped down and the ones with "wear" will be donated to the Nike Town in San Francisco to be recycled. The shoes is broken into three parts and used in tracks, tennis courts and basketball gyms. (see Nike's Re-use a Shoe website for more info).
If you happen to run with friends and plan to race an event together, see if you can organize a car pool. Meet up at a local Starbucks or McDonald's (but don't eat a burger) and pile into a car to ride together. I'm fortunate enough to train with great friends and often we register for events that several of us would like to do. This allows us not only to train together, but we can organize before so that we limit the number of cars making the drive. This works for us runners and for our support crew. If you've been part of a support crew, you know how difficult it can be to try to find parking.
Those are just a few tips we can keep in mind while we are running and training. Also, check to see if your local event is taking steps to be more green and how you can take part in helping the cause. Enjoy the rest of St. Patrick's Day and if you have Nike Free's on, i think you are covered for your green... but you still might get pinched.