Stairways Software has released a significant update to the popular macro utility Keyboard Maestro [1]. Version 4.0 overhauls the user interface, adds 64-bit support, and adds support for Growl notifications. Macros can now be executed when hot keys are pressed, held down, or released. Also, Command-Tab can now be used as a hot key, the program switcher can optionally hide all other programs when switching, and the clipboard switcher now offers both a search feature and display of images and rich text. Version 4.0 requires Mac OS X 10.5 or later. ($36 new, $18 upgrade, 7.6 MB)
[1]: http://www.keyboardmaestro.com/