"Other" memory usage

Hey, I synced my iPod Touch a couple of days ago and I noticed that the "other" memory usage had shot up to above 1GB.

One of my suspicions is that I recently uninstalled dropbox, and the files off that have stayed on the device, that could be a load of rubbish.

I was wondering why this might be, and more importantly how do can get rid of it? It's not jailbroken or anything.

Thanks in advance.