Are there any Q&A sites that are similar to yahoo answers, that pay money?

Actually, I ran across one the other day because someone else asked about it. It is called Answerpedia and if you get over 10,000 points there, supposedly you can cash them in for money through paypal. The catch is, you only get "paid" points for being chosen as Best Answer, not for simply answering. And it isn't a flat 10 points per BA. It is whatever the person asking is willing to "pay" in points for an answer. Which can be as little as 1 point, or as many as several thousand. The other things seems to be that it isn't as large or active as this site, either.

Not unless you're qualified in a field. People will only pay for professional advice, not possibly wrong advice from random people on the internet.

If on the off chance you happen to be a GP, there are loads of healthtap/netdoctor type websites which you can set up an account on through your practise.

PrestoExperts (the old LivePerson) is one, but you really must be an expert in an area and it takes lots of time and effort to get anyone to pick you to answer there questions. A casual user will not succeed.

Depending on what specific topic you have in mind, you may want to look into forums.