This is pretty much common sense but i post it anyways because its pretty nice to avoid walking long ways without mounts.
All you need is the Lag7 Tool (http://www.ownedcore.com/forums/worl...c-lagtool.html (Lag7 Strategic Lagtool))
Set it to 6-8 Seconds (too high gets you disconnected).
Start to Roll. Then press Lag-Hotkey.
Due to the short CD Time of the Roll you're able to Roll just again after your out the lag.
But remember, you cant control the direction while rolling. You just roll straigt forward.
http://img6.imagebanana.com/img/dce0zjrr/lagmacro1.jpg
This will most likely work in the Release MoP version, too.