Hello,
I am a complete newbie, but your website caught my attention. I am currently attending college in Atlanta, Ga, but plan on moving to Hawaii in December. I am an english major, but have always been interested and concerned about our ever-threatened environment. Finding someway to incorporate the two has been a goal of mine recently. Anyway, as far as the idea for planting trees, I think it is a wonderful way for the "regular Joe," who may not have the means to help environmentally on a global scale, to feel they are contributing within their community. I found this website, which may have what you are looking for:
http://www.arborday.org/programs/treecity/map.cfm 