Today (April 22nd) is Earth Day 2011, and the theme of this year's Earth Day is A Billion Acts of Green. The basic idea is that if at least a billion of us each pledged to perform some relatively simple "act of green", we'd be that much closer to a greener, more sustainable world. Here are examples of three simple, relatively low cost (lightweight, if you will), but very definite and effective, acts of green that could help make a big difference if performed in large numbers. All are tasks I've already accomplished myself, and have reported in detail elsewhere. So, with all that in mind, here goes... [ . . . ]