To me a hobby is more fulfilling when it is something that you do instead of something you that you buy. If you like collecting stuff then you're probably going to have to buy that stuff (stamps, comics, antiques) unless you do some dumpster diving for stuff (interesting bottles, ashtrays). But, you could start with reading or walking or gardening instead (a lot more to do with less expense). Also, you COULD just hang out at Yahoo Answers day and night and become a Top Contrib (as you can tell, I'm not there yet). You could also get a web camera and film yourself doing dumb stuff and post it on youtube...~you could come out on the national media!~.
