I made a few cents selling google ads next to a version of the bubblebreaker game I built. Seems to be hard to make money on games...
http://games.jeffslutz.com/bubblebreaker/
Been earning a couple hundred per year with a time-tracking/report-generating site for therapists-in-training. I think one of the big downfalls of the concept was that I chose too small of a niche to serve (marriage and family therapists in training in the US). The most tangible benefit from building the service was the coding knowledge gained which serves my freelance work very well. http://www.therapyhourstracker.com/