In my foray into gaming mouses, one interesting discovery is the “Logitech G13 Advanced Gameboard”.
After reading the many reviews and going to a local shop to see it, i think this is fantastic. Not just for gaming, but most importantly, it has 22 programable keys. The greatness of the programable keys isn't just from the company's spin-doctors, but highly liked from user reviews. The software is actually quite good, and comes with a programing language using Lua. So, if you are a emacs user with its 3 thousand commands, and or 3D modeler, Second Life player, this extra keypad will be extremely useful.
There are many gaming keyboard out there. For example, the most popular ones are:
For review, see: Gaming Keyboards for Programers (Emacs, Linux, Blender, …)
They all have many programable buttons and keys and some have displays and knobs. I LOVE these extra buttons and knobs.
However, they all have one major usability problem: They are not ergonomic. So, if you type few hours a day, chat in games, or writing blogs or emails, these keyboard are pretty unusable.
A optimal setup is to get one of those high quality ergonomic keyboard, then, get a programable keypad such as the G13.
The G13 is often compared to the Razer Nostromo Gaming Keypad. Go over there for a comparative review.