I hate to have any clocks visible when I'm working, but after hiding all my clocks, sometimes I need to know quickly what time it is. I created this little app a few years ago to be opened quickly with QuickSilver/LaunchBar/Alfred to check the time. Finally got around to cleaning it up a bit and posting it.
Latest version is available from here - https://github.com/downloads/zachwaugh/Clock.app/Clock-1.1.zip (10.7 or later)