The Sheet Music Exchange project that was previously mentioned here has a new permanent address:
http://www.sheetexchange.com/
(The old address will still work for now but please update your bookmarks.)
Thanks to everyone who helped, I have added features and fixes and have even started a small blog with latest changes and more.
While at least for now the project is focused on Persian music (because there already was a site for other stuff) anyone is welcome to add a list of their sheets.
