I'm only pulling 20mA max - so current limit isn't much of an issue. I've never actuall had an issue with the 78XX however I see on running on a 24V system that I could get surge voltages over 40V. I was also thinking of just using a Zener and a resistor to regulate the voltage - but that would lead to poor efficiencys since I want to run it both on 12 and 24V. Thanks all for your input - I think I'm going to be uding the transil TVS diodes