Unnaturally tempted by this project, which has created a common platform for cartridge dumping w/ standard adapters for the major consoles. It auto-recognizes which type of cart you connect, too!
The Universal Mega Dumper (UMD) is a game catridge read/writer project designed around a Teensy++ microcontroller. The universality comes from the UMD’s ability to support many different types of catridge connectors by having general purpose 16 bit data and 24 bit address paths along with a dozen control signals – all of which can be customized for each game cartridge mode.
More on the project page.