I just found a very nice alternative to the Mac OS X twitter client Nambu: Twit Menulet, a Twitter client that fits in your mac menu bar. Like Nambu, Twit Menulet has a little icon in the Mac OS X menu bar. But Twit Menulet does not have an application window. All actions are done over the Twit Menulet menu in the menu bar. Give it a try – I’ll do!