Some thing that I found.

[zora man]

CLICK OR DIE!!!!! (http://www.gamecabinetsinc.com/joystickkit.htm)
Well I was playing with raine when I thought it would be cool to use a arcade box thinger instead of this keyboard so I did alittle research and found this.:)
It's alittle expensive but it is worth it as soon as I get enough money I am ordering one!
So tell me what is your dream design?

[carrot red]

Cool idea, but I wouldn't know how to design one.

[MottZilla]

I want an Mortal Kombat original mint control panel. Infact I want the entire cabinet.

All it takes to build your own controller is buying a few parts, basic shop skills, and putting together some wires.

I just bought an adaptor as it's cheaper and easier than making a dedicated controller. Also this way I can just use a gamepad, or buy a arcade style stick, and just hook it up to the adaptor.

If you are really interested in building something, build what is often refered to as a "Super Gun" or "Jamma Rig". You can ussually pick up older games for very cheap. Forinstance you can get a Street Fighter 2 set for 10$s.

[Flash Man]

http://www.geocities.com/lusosarge2000/eindex.html

MAME Arcade, much much better hardware on that page is a little outdated though, but for most games I'm sure it would work.