This seems quite obvious, so apologies if this has been suggested already, but...
Take that iCade cabinet you have leftover, grab a PI, an old screen - an see how cheaply you can make a MAME cabinet. No fancy laser etching lathing or printing, just old school budget modding.
I think it would be great to have an episode that people could follow, and make their own gadget - the iCade seems like a solid and well built piece of kit, but with a fairly narrow userbase and support. You already ripped out the controller board, so why not grab a cheap USB keyboard and hardwire the controls to that. Think budget, a project that can be completed quite cheaply and easily and needs just basic technical skills - but still ends up with an awesome mini arcade cabinet worth probably double what it cost to make.
An iCade cabinet costs about $80, a PI about $30, and an old screen that size, probably around $50... compared to a handful of games on the iPad, and an all out cost of about $600 - well it could be the start of something wonderfull.
I watch all your videos and spend most of the time wishing I had your workshop, I don't have a workshop and routers and lathes and god-knows-what-else - I have an old table and a cheap drill, I wanna play too!. I actually have a mini cabinet project underway using a GP2X, but I'm really intruiged to see how the PI would fare in it's place.
