USF Player Found by patrick at 4:59 AM EST on January 5, 2006
If you are finding it hard to configure Winamp to play your USF files, use Coolplayer. (http://coolplayer.sourceforge.net/?plugins) All you have to do is download the ZIP file and extract the program. Then you put the 64th note DLLs into the same folder, open the program and VOILA! you can open your USF files by right-clicking the menu bar. To get your USF's to show up, set the File type to 'All Files'. Hope this helps!
I wasn't very happy with Coolplayer when I tried it out... though it did work. XMPlay also supports Winamp plugins, and has a better user interface, if you want something besides Winamp.