Victoria, I think the OP is talking about processing retail rebates. You know, those forms you hate to send in and maybe eight weeks later if you're lucky you'll get a check.
I've read that there are some non-profits that make some decent side income processing rebates for large companies. This is a job that requires human beings - someone has to check that the forms are filled in correctly and all of the supporting documentation is enclosed.
Having said that, a quick Google check shows that anyone considering doing this needs to vet specific companies carefully.
Dang, that reminds me - I need to go jump through some hoops for $15...