This is a clock that auto-fits into the title bar - saves space in the system tray
Requirements:
Windows 2000 or later (for transparency)

EDIT:
v2 - allows a registry setting TimeFormat (string) which overrides the settings pulled from the Regional control panel.  Uses wildcards like these
For example, %#c shows the date (in long format) as well as the time.  AM/PM can be added via %#c %p which yields -- to use the date in the documentation --
Tuesday, March 14, 1995, 12:41:29 PM

v2.1 - fixed bug where if you dragged it close to the left edge of the screen, the next launch would force it to be at least a few hundred pixels away from the left edge