I've seen several guys who used DB-9 and other "computer" connectors to do plug blocks. It's not hard, and you get get all the parts at any number of on-line electronics parts suppliers. And you can have a shared ground and power if you want (though make sure if you do that, you use big enough wire, a single 22guage wire isn't going to cut it for 6+ digital servos for the hot and ground leads.