I'm a butcher and I take my knives into the shop and sharpen them there. We have 3 at the shop. one is a disk grinder, one is a belt grinder with a sandpaper belt and the other is a 3 edge stone. I use them all. You have to be carefull with the belt grinder tho. You don't want to scorch the blade as it will never get sharp again........ ok, maybe after you grind about 1/4" of steel away.
For the avg person the Lansky is the way to go.