Gyro meat--I love it. How can someone make this at home?

The greek restaurants around me are selfish and won't share a chunk of it, you know the big 5-10 lbs hunks that twirl around the heat lamps. Does anybody know a great recipe that would come close to duplicating this. I know most are a combination of lamb and beef. I'd like to throw a Greek themed party sometime with this as one of my dishes.