My arcade
I was showing this to Cisconinja earlier and he mentioned some other members would like to see this, so here a link to my arcade project.
http://segasaturngroup.proboards.com/index.cgi?board=hardware&action=dis...
To make a long story short I bought an arcade machine, and modded the living daylights out of it to add 8 systems to a singe cabinet. The build process walks through everything from my initial purchase to the custom wiring harnesses, junction box, and a good few other hardware hacks. As it stands today I have a modded xbox, Original St-v Motherboard with Die Hard Arcade, Xmen V. Street fighter(cps2), and Sega Saturn. Im currently working on a custom jamma converter for the Dreamcast. Additionally, I have most of the parts to add a MVS and various neo-geo games. And i still have room to grow 
All the mods completed have been piece milled together from ungodly amounts of time on google. Thanks to the original arcage hackers and multijamma.com.
PS. I Hear some other members have some pretty rocking arcades also, Id love to hear some feed back!
Cheers.
EvX