KeyCastr is a small Mac app that shows keystrokes as you perform them. This is useful especially for screencasts when you need to know what was pressed. The only Windows app I could find that does something similar is osdHotKey.
Edit: KeyJedi has been made known to me through the comments. Thanks Hüseyin Tüfekçilerli.
October 2nd, 2008 at 16:43
Check out the KeyJedi from Roy Osherove:
http://files.osherove.com/downloads/KeyJedi.zip
October 2nd, 2008 at 17:29
Awesome. If anyone is looking for the homepage to KeyJedi here it is:
http://weblogs.asp.net/rosherove/archive/2007/05/29/key-jedi-1-03-renamed-from-shortwatcher.aspx