Wow - I have had two good experiences with Staples lately. I was able to complete a rebate form online and didn't have to mail anything in, and my check came within 2-3 weeks.

I always make copies, too, when I mail in rebates. Even though I no longer have the original, I have found the people don't give me a hard time if I tell them "I have a copy of what I mailed in right here".