If you're someone that uses the pay-per-incident Professional Support in Australia (13 16 30), then you may be interested in Professional Support Advantage, a new support offering that we're piloting at the moment, accepting signups until mid-October.
 
What's the Advantage? Once your PSA contract is set up, you can log support calls 24x7, and billing is invoiced - no credit card required when you call. Just to let you know up front: there's an annual administration fee, and calls worked after hours are more expensive.
 
[Updated links 18/07/2004]
If you're interested, you can read the overview here: Microsoft Professional Support Advantage .
A list of all Support Services currently available in Australia is here.