[QUOTE=wrx-sti]BIG waste of money[/QUOTE]
Unless you're on good terms with the tyre shop and dont pay any extra :D

i had mine filled with nitrogen, but when i had a service, they let it out and filled with normal air saying there was not much point unless i was gonna be doing track work.

i have nitrogen in my tyres, mainly coz it doesnt cost me anything. But over a 3 month period i only drop about 0.8psi from my tyres (last time round ne way)