Apple's Dashboard, included in Mac OS X 10.4 (Tiger) utilizes mini-applications, easily customized, and hidden away for viewing at user's preference, without taking up valuable real estate. Though some thought Apple ripped off Konfabulator (now Yahoo! widgets), Apple has managed to engage the developer community well, which has seen terrific innovation. Some of my favorites, which I use with some frequency, are below.
Listening to ''After Love (New Short Cut)'', by Piet Blank & Jaspa Jones (Play Count: 1)