You might want to try something like LiveOps or West. They are virtual call centers so you take the calls in your own home. You only have to take a few calls every 60 days to stay active but you can pick up as many hours as they have available.
I am waiting to start. I also work full time and need to schedule extra work around my twins schedules (if you can call them that). There is alot of good information about work at home (legitimate) opportunities at
www.wahm.com (work at home moms). People are very honest about their experiences with companies on the message boards.
Good luck.
Lori