Vimfuego developed a new hardware device for the Commodore 64. With the device you have a 100% internal Reset switch and ROM selector, with no ugly external switches on your C64. The switch works together with the Restore key and is based on a Arduino Pro Mini. Vimfuego can program the kit but you need to install it yourself which includes soldering wires.
Website: http://www.lemon64.com