Something which I always thought might be interesting would be like an all-English after school care service. You know, instead of sending kid off to Anqinban or whatever after school they send the kid to you one or two days a week, maybe $1,000/day. You feed, look after and have fun with them in English - so maybe like Mondays and Fridays, so twice a week, $1,000/day, four kids a day. Take them home, feed them, take them to the park or arrange a game or watch a movie or something similar (something that your son would enjoy as well). Just all English. Some parents wouldn't like it because there wouldn't be time to do their homework (apart from English homework), but some parents would like it (I'm thinking parents of kids at international schools or bilingual schools would be interested). And for you it's only two days a week, and as my aunt said - she can either get a job and pay someone to look after her kid, or look after other people's kids and spend more time with her own.
This sounds very promising to me. I've had loads of people interested in their children spending time with my son because he's a native English speaker. I even had one complete stranger stop me in the street to ask for a play date with his four year old.
Nice to see you back Housecat. Hope your son's okay.