I've started doing freelance writing work at textbroker.com.
Pretty solid site...I like them so far. You submit a writing sample, and they rate you from Level 2-4 based on your ability. Your rating is used to determine how much you make per word. For example, based on my writing sample I was given a rating of 4, which is the highest a new author can get through the site. I make $0.014 per word, which translates to $7 per 500 words. I can typically write 1000 words in about an hour with research included, so that puts me at about $14/hour to sit on my computer and type away about whatever junk people want written.
There is no shortage of work, either. Currently there are about 2400 articles available for writing, and I've been averaging about 2000 words per day (2-2.5 hours of work for me). That's $28/day, which adds up if you do this even 15-20 days per month. I take it pretty easy, but if you wanted to do 3000-4000 words each day you could really do pretty well for yourself.
The topics can be dull, but I find it fun in a way. One client today had a request for someone to do 800-1000 words on nursing school grants for men. And yep, I did it. 1000 words on the dot in a little over an hour (I really had to research the topic), which is a decent hourly rate for sitting there at your computer.
Anyway, proper spelling, punctuation, grammar, etc. is a must if you want to do Level 4 work. Level 3 writing pays out $0.01 per word ($5 per 500 words), and Level 2 pays $0.007 per word ($3.50 per 500 words). I'm pushing to get a Level 5 rating, which pays $0.05 per word ($25 per 500 words), which is a pretty nice pay raise from $7. It's apparently very tough to get (you need to be spot-on with everything from style to grammar), but that's something that's worth working toward.