I've shopped for Service Intelligence before. It's a good company. My favorite was
www.trendsource.com
I don't do much MS anymore..... I've switched full time to couponing instead.

If you have a CVS nearby, come join us in the
CVS forum! That's a fun way to occupy your summer time and save money on things you need (like getting toothpaste for free)... in my experience, couponing has been a more worthwhile hobby than mystery shopping and has contributed more to the family finances.
(By the way, I promote the CVS forum b/c I'm the mod there, but you should check out the forum for your nearest grocery stores too - lots of money to be saved in couponing!

)