I would say UO was the first game that I really multi-boxed with. Having another toon that would stand there for hours on end while you beat on them to get your weapon skills up with was extremely useful. So was the stealing ability. I remember setting up one toon who was a grand master snoop/steal in the Brit provisioner shop and swipe peoples items. Guards would insta kill you and I used my other account to loot the corpse. Ahh those were the days...