I don't know of any reliable free bins specifically for USB drives, some of the expensive network recycle bins will doubtless work.
But you can use a simple trick to ensure that you don't lose files on your USB drives.
Make a folder on the drive, call it "Deleted Files" or something similar. Make it hidden using file properties or only allow admin access etc, whatever you like;
Now add that folder to your "Send To" context menu using "Send To Toys
Now you can send any files to that hidden folder instead of deleting them.
This does not of course have the same functionality as the normal recycle bin, but you wont lose any files, and nobody else will see them unless they look for hidden files.
This will work for network drives; http://coolstuff.ws/software/netrbin
But I don't know if it works on USB drives connected to a standalone machine. I don't have it on this machine to try it. It only costs ten dollars, and you can get a free trial before you buy it. Worth a try. There are a couple of other similar utilities in that price range, but after that the price goes way up!
This is probably about the best, but it starts at 60$ for a single license; http://www.diskeeper.com/business/undelete/