Up for sale is my custom Sega Genesis portable. It takes 6AA batteries, gets about 8 hours of battery life (far more than the Nomad), uses all original Sega buttons with a Game Boy Color D-pad, and sports a vibrant, TFT 2.5" LCD screen. I'll also include 2 6-button Genesis controllers, as well as the following games:

Sonic the Hedgehog
Sonic the Hedgehog II
Sonic & Knuckles
SpiderMan: Maximum Carnage
Ristar
Samurai Showdown
Super Thunder Blade

Link to pictures, making-of, and features

So, anyone interested?