I think it was a cheque from that site "Treasure Trooper" (don't know if it's still around) when I was quite young. Basically, you sign up for all this stuff and the site makes money from the advertisers, and then they split it with you, lol. It was like 40 bucks or something, but it felt magical to make money and not have worked a normal job for it. Of course, all of the spam and junk mail that followed wasn't too awesome.