Airbag light on means a fault has been detected in the airbag system, so the system has been disabled. Dont worry, it wont go off in your face.
The car is perfectly safe and legal to drive but, because the airbag will not deploy, is slightly less safe to crash!
Having the airbag light on is NOT an mot failure.
If it was my car I'd get it plugged in to the relevant diagnostic equipment to get the fault codes and reset the light.
Phone around for the best price, main dealers tend to be expensive, lots of independents have diagnostics gear.
If it stays off that's fine, if it comes back on you can use the codes to work out where the fault is.
If money is tight (or you just cant be bothered) you can just ignore it.
gus
March 2010