Ehow is a website where you can write "how to" articles about anything you want and they will pay you a portion of the ad revenue that is generated from your articles. It's nice because you can do the work once and they'll keep paying you as long as your articles are making them money. I'm averaging about $10 a month off of 20 articles right now, so I think you'd need to write in volume to see a decent monthly income over time.
What I like to do is write my articles and then submit them to multiple sites, like eHow, Associated Content (they pay upfront, btw), Squidoo, etc...
ChaCha, on the other hand, is hard to recommend because of the recent pay cuts they've made. Regular SMS guides make 10 cents per query. If a guide answers 200 questions or more with a quality score of 95% and up, then they will make 20 cents per query the next week. You have to continually meet the requirement each week to get that bonus, though. It sucks.
They have another position that Jerry really likes because the work is a lot faster and involves categorizing the questions as they come in. The downside is that it only pays 2 cents per query. Might as well work in a sweatshop, if you ask me.
Here's a couple of articles I wrote about different online jobs and writing online:
Hope that helps! Good luck. :)