a simple panel that could be docked somewhere and configured to show things like play history based on artists, genres or moods
maybe it could be changed to show a tag cloud based on entire collection or a filter as an option
based on a quick google seems like there are ways to do a sql query and generate one from that, http://www.petefreitag.com/item/396.cfm (how to make a tag cloud) , some of the comments on that page have more links
helium has had this feature for a while for artists and genres so should be doable in mediamonkey, any thoughts?
just made this up from by exporting last 1000 genre play data into this web app: http://tagcrowd.com/

or by recently played artists..
