I clean small offices after hours. Even doing one a night could net you several hundred dollars extra a month. And, the start up isn t very much. I have more information, tips and resources for you on my Squidoo lens-the link is in my Profile.
You need to advertise but with a full time job then that would be a lot of work if you have the energy and the time then start looking. Ask your boss when you are due for a rise.