There is, but you're better of doing file operations outside of PP using a proper file manager like Windows Explorer or Finder. (And ideally before you import files into PP.)
Normally, i put all of my stuff into the project folder in finder but sometimes i am putting things on the desktop such as stills i get from istock or whereever.
But if premier can make that process a bit more automated then i would like to know how. So i will check out the media manager and see what gives.
I always structure my Project's folders, for the types of Assets, that I will be working with. Then, I Copy my Assets to those folders, prior to Importing. This is my general layout: http://forums.adobe.com/thread/919388?tstart=0
In my case, I always work with Copies (except for Capture from miniDV tape), keeping my original Assets on my NAS.
I do very similar with my Bins in PrPro, though might break down some, into sub-categories, to help keep things neater, and easier to find, in a large Project.