There are a couple of brands that come to mind. The 3M Super77 (sold at Walmart and other places) and there's a cheaper brand that I use sold at the same place. They both work equally well, especially for something non-critical like attaching sandpaper to blocks and straight edges.
I've been doing that for years without problems.
Super 77 is great stuff. I use it a lot, and it's very sticky. Sometimes I've had trouble getting sandpaper of my sanding blocks and stuff, though, so you might be a little careful about it. I don't use it on my radius blocks (wood, not metal) for that reason.
Contact cements can be brutal to disassemble if you use as directed. That is: coat both surfaces, let them partially dry, then position. The stuff is amazing, but getting it apart is very hard. One way to cut down on the adhesive strength is to coat only one side (I'd spray the block) then let it set up so it isn't tacky. Attach the paper. The result should be that the paper will come off easier and you can remove the residue from the block with your finger.
