Eggs Hatch SUPER,SUPER Fast
First, get an egg you want to hatch. Get a Pokemon with Magma Armor OR Flame Body (Just catch a Slugma). In your party, put the Slugma just BEFORE the egg. Then, go to Lavaridge town, I forget. JUST GO TO THE TOWN THAT HAS FLANNERY AS A GYM LEADER. Go in the Pokemon Center and go through the blue door thing. Go in the Spa and start RUNNING around. The Egg should hatch in 2500 steps.