I think it would be cool if you could do an arcade stick build. Ideally it would work with PC for playing MAME games and other PC games, but also be able to be used with other consoles as well. I've seen multi-console PCB's on sale but I guess you could also wire up other console controller PCBs for multi-console support. I also think it would be cool to have a bluetooth option to connect to PC. This type of build guide could be used to help people that want to build their own full size arcade cabinet too.