An online file storage manager

In my younger days, I had bought a fairly low in size (2gb) flash drive, and I was wondering if there is some utility that would allow me to connect to an online storage manager. In other words, I am looking for a portable utility that would allow me to "upgrade" my flash drive storage capacity via connection to my online storage.

For example, box.net can be mounted as a hard drive though WebDav using the Windows http://techie-buzz.com/technology-buzz/mount-box.net-account-in-windows-...

I was wondering if some {portable} program like this exists. Or, if there is another way through some other means (like Mozy through Filezilla).

Thanks!