I am a part of several survey sites, but like others have mentioned, it's not a big money maker. Actually, it's really not even a little money maker. :) The majority of them promise you big bucks, but don't deliver. There are very few legitimate sites. I do belong to Survey Savvy. In the 2+ years that I have done surveys for them (which you have to answer prelim questions for and don't always qualify to take the full blown survey), I have earned $212. So like I said above, it's not a big money maker...and this is my biggest one! LOL If you are interested in joining (they are one of the few that you don't get spam because of), below is a link. It's "my" link, so if you decide to join through my link, I get some sort of credit.
To sign up, click on the following link:
http://www.surveysavvy.com/ss/ss_index.php?id=1814624&...
I also belong to MySurvey. With them, you build up points and can trade them in for gift certificates, prizes or cash. The majority of their surveys pay you 10 points for the initial survey, then if you meet the qualifications and continue with the survey, it pays more points. The more points you earn, the bigger check you can request, but it takes awhile. No survey site that I know of offers a quick turn around. Again, here's "my" link for MySurvey if you want to join.
http://fun.mysurvey.com/join.cfm?r=2775945
To be honest, for both of the sites above, I save up my points. Then, around the beginning of November, I turn in my points for cash so that I can have some "unexpected" extra money for Christmas. It's worked for me for the last two Christmasses and it was nice to have some additional funds. A part-time job it is not, but I think it's fun, doesn't take much time (neither site sends daily emails...it's usually 3 or 4 a month) and it has allowed me to have a little extra money at a time when I needed it.
H.