Well, on my G1 I had a University of Michigan magnet there. I plan to keep it clean for now, but would like the option in the future.Maybe advertising space for a general contracting company or something? I plan to put some there for my business when I buy one.
Acetone should also work if you don't own any GooGone but do have some acetone laying around.I speak with some expert knowledge on the subject. There just stuck on with 3M tape. When my truck was rear-ended two years ago. The body shop purchased the rear emblems. I told them to leave them off. They're sitting on my desk at this point.
To remove them, use Dental floss. Saw through the adhesive backing. Remove the remaining residue with Goo-Gone. That's all there is to it.