I've also used my ErgoDex at work along with CodeRush to have one button access to refactoring, class creation, quick navigation and a number of other VS.NET HotKeys.
Why have a pad like this you ask? There's a few simple reasons:
A keyboard is designed for prose, not hotkeys. The whole F1-F12 thing is a hack and we never get F1 anyway. Eleven lousy keys unless we want to hold down Ctrl-Alt-Shift?
I personally play one game at a time until I'm sick of it. The ErgoPad can change whenever I want it to, but this one will stay in this config until the next game I dig.
I like the idea of a totally custom controller/keypad for absolutely any reason I like. The ErgoDex also comes with Macro support for all the Microsoft Office apps and it even detects things you've got installed. It automatically sets up profiles for FarCry and Doom 3.
I also like the idea of putting the keyboard elsewhere out of site and gaming with just this specialized pad (25 keys that are set up the way I want rather than 101 keys that are set up like a typewriter) and the mouse.
I hate being I/O bound by the hardware I interface to the computer with. I'd like to use pads, mice, voice and pens all at the same time.
Recommended for anyone serious about interfacing with their computer effectively.
link to original: http://www.hanselman.com/blog/GuildWarsAndTheErgoDexDX1.aspx