USB tools and Portable programsThough USB portable drive was initially used only for file storage proposes, today, it's more than that. It has innumerous uses to say like one can carry entire Operating system in it, lousy and troublesome Floppy drives has been replaced, acts as a quickest means of data transfer and storage. Moreover it is acting as a physical RAM(memory) in windows Vista(Readyboost). Not only this, software developers have broaden the idea of portable applications. That means we can carry any kind of Windows(OS) dependent applications independently in flash portable devices. This certainly has increased one's productivity.
Just take portable applications of your choice,start working on your favourite application on any machine and personalise any computers in world according to your taste.
To get all the whistles and bells, we must have at least 512 MB of storage on Flash drives. Now, coming to the point, the following site has comprehensive list of portable application for your portable flash drives. Open Source as well as commercial one. Take a look in it, and feel blessed.