Calling on teh power of the f-list

Anyone here familiar with USB flash drives? Specifically USB flashdrives that aren't deleting properly? I've dragged the files from the drive to the trash and the drive shows up empty each time I insert it, but the space is still taken up and the files show up if I run a virus scan. Some of the files are PC to Mac transfers, and I'm working with a Mac. Disk utility first aid does nothing. I'm hesitant to try Disk utility erase since it's supposed to be used with a CD-RW or a DVD-RW. I think the computer was made before the flash drive was in common use (August 2004?). There's nothing on the drive I can't lose, but I'd rather not lose the drive itself.

Y'all were awesome on the zipping question, so let the brain picking commence:)