My sister had told me about this phenomenon in Paris around 6 months ago, and I know now that's it's also been happening in NYC and the UK (and probably many more places) for a while.
It's an article in the April issue of Marie Claire US that brought it to my attention again. As they put it in the article, Freegans are "radical environmentalists (typically vegan) who reject our wasteful consumer culture by living almost entirely on what others throw away".
This article only makes the magazine worth buying but you can wait for someone to throw it away. wink wink.
No, seriously, I think we all need reminders to kick up a notch our earth-conscious habits.
Here are 2 youtube movies to explain:
Alf from the UK
Other useful websites:
July 08 article in the daily news
June 07 article in the NY times