In one word: the new user groups system is FANTASTIC. OUTSTANDING. That was a masterpiece, Nir. In the old days, sharing stuff with users from Group A got you banned by users from Group B before because they did not agree with the political message embedded within the music (e. g. songs that critically deal with the Islam).
Now things have changed, since Group B users <em>would not even know</em> you're still sharing that! (heh heh) :P
However, my user group system has gotten REAL complex by now. In short: I don't see thru anymore. Hence, I would appreciate it a lot if I could sort by directory or by user group in the Options->File Sharing dialog.