When you turn Search on it only gives you a default set and ignores all the custom searches that you spend lots of time carefully building.\n\nDIIGO, WAKE UP AND RESPOND!

Roll your own social collaboration site, collaborate the way that you want to.  Excellent and stable.  This one really has it all, you choose what you want and create your own space.  This service has been around for awhile, I don't understand why it's not better known, it's one of the best services on the web.