How about being a blogger for other people or companies? You can search on google or offer your writing services to other bloggers or local small businesses. While companies are realizing the value of online social marketing, many don't have the time or money to do it.
You can offer to do a facebook page and update for a reasonable amount. Or email marketing, be creative. If you worked for ten businesses at $100 a month each - that is an easy $1000 a month from home.