Watched the video on bumptop from the link on 43 folders. Bumptop is a new desktop interface prototype. Many of the user interface metaphors are similar to a real (physical) desktop; moving files around, stacking, shuffling things. The critique on 43 folders, linked above, addresses several of the limitations.
On the PLUS side, the "zip" motion of circling and drawing a line through the middle is innovative. I can see using that interface in favor of the CTL-CLICK-CLICK-CLICK method I currently use. Circle, zip through the middle, post to flickr. Easy.