Taking photos of the homeless or tramps is as easy as you want to make it. Have a pocket filled with some £1 coins, take your photo and drop a coin or two into the guy's or girl's hat. Talk to them and ask themhow they are. They are human like anyone else. Most enjoy a chat and can be quite intellectual an philosophical. See here:
http://www.flickr.com/photos/amazons...n/photostream/