What sort of services do well now? Offering services such as blog commenting and article writing does well, what else?
There seem to be a buzz about all kinds of applications written on the Twitter API. You may want to look at that direction. You weren't asking about this obviously, but you may want to think about moving up the ladder too. That is, instead of giving blog commenting or article writing services which unfortunately are too high in supply and thus not lucrative, you can get to learn some other skills. If the links in your signature go to your sites (and so if you are into Wordpress), that may be one route to take. People selling premium templates make LOTS of money. Go with the trends. People are on the lookout for WP membership plugins. Design a theme that complements this need for instance?
I hear strippers can make quite a bit... if that's the kind of service you want to offer. If you're a good writer you can do very well writing articles, but you're stuff has to be premium otherwise assume $3 for 300 words. If you are a good designer, wordpress themes and templates would be good. Pretty much do what you are good at and MAKE the service do well.
For any of these services that were listed, I have always used the people at elance.com. Those people will work for a very reasonable wage and save you tons of time.