Badda boom
Okiedokie, I used this on my Necro for a while.
Basically, you keep moving, and cast the spell. Where you started casting the spell creates a *Save point* when the spell is about to fire, you are wapred back to the saved point and then as soon as the spell fires completely you are warped back to the place you where at before you were warped to the save spot.
Anyone around you can notice this, your character can be seen every time he/she goes back and forth from the *save point* i dont recall if you can be seen on the map. but bare eye to the character its very noticable.
Now. Even tho this plug takes you back as tho you hadnt moved, you have a decent chance at a fail on the cast. (something i found was reduced by an AA, cant remember the name) but personally, if i can keep moving i think a fail or 2 is worth being able to run and cast.
*Tip* i foun that if you completely stop moving right before the cast fires, you get a better success rate*
Also, As above said, /scast on/off to make it work, as well as (make an ingame keypress macro)
/scast "Spell name" you need the ""