mom2boys,
Here is a breakdown of what you can get right now.
Mypoints and blink can be used to get webcertificates. You can use webcertificates to buy passes.
Searchcactus sends cash, which of course can be used for anything.
Milesource, you can get a variety of restaurant gift certificates, such as Rain Forest Cafe, Planet Hollywood, Olive Garden etc..
Is it worth it? In my case it is, I am a stay at home mom and the time that I am doing the programs, well, I would be on the computer at that time anyway. The way I also look at it is, anything that will help out with the trip is time well spent.