Too Many Social Bookmarking Sites
Ma.gnolia Social Bookmarking
Somebody needs to write a Firefox extension that allows a person to post bookmarks to multiple "bookmarking" sites: del.icio.us, digg, reddit, Ma.gnolia. (This would be easier if they all supported the Atom API.)
Can't forget Simpy! I think there are bookmarklets that do mass-add.
If someone builds this extension they might also add www.blinklist.com. Mike