Windows: If you've found yourself wishing that your flash drive had a recycle bin so that your portable apps and documents had the same safety net that your desktop files do, iBin brings recycle bin functionality to your flash drive.
iBin is a small — 700k — stand-alone portable application. Place it on your flash drive and run it and create the iBin folder that will be your portable recycle bin. If you have a large flash drive with a lot of files we'd suggest running it for the first time when you're not going anywhere. iBin indexes the entire drive to build a list of files it should protect and send to the recycle bin; it took about 10 minutes for the initial indexing of a 4GB drive at around 95 per cent capacity with small documents and images.
Once iBin has finished the initial drive index it's quite snappy. It comes with a well-written manual, but if you skip reading it at least note that in order to delete a file from the flash drive while iBin is running you'll need to hit WIN+DEL not just the delete key — iBin intercepts the standard delete if it is performed on a file it has indexed. All files you delete with iBin end up in X:iBin where X is the letter of your flash drive. In the Custom Options menu of iBin you can specify what happens on deletion, how files are restored, how big the recycle bin should be, and if iBin should auto-clean the recycle bin.
iBin is freeware, Windows only. If you have a portable application that helps you bring desktop functionality with you, let's hear about it in the comments.