I own a blog that reviews different websites that offer payment for people that work on them. There are several Q & A sites out there that hire experts to answer questions and pays them for their response. During my research and testing different sites, I cam to know this site through a friend of mine. They suggested that I join on here after another site I was on stopped paying people to answer questions. I had been on this site for several years and liked how it was. Unfortunately, they ran into some funding problems when Google Adsense closed down their account. Therefore, they could no longer pay people for working there. The last time I heard they were trying to find new funding and open back up the rewards program and pay people again for answering questions on the site.
I know of several other Q & A sites that offer rewards to people to answer questions. However, all these sites need a person to register and make an account. The only possibility is to write a question on a forum as a guest. I think some forums will allow you to ask a question on there without registering. But in general, all sites wants a person to register so they can verify they are a person and not a bot or a spammer.