Low quiescent current 5v regulator ?

[Pippin1066]

I'm building a microcontroller based device, powered from 12v ( 8 AA cells ).
The micro runs on 5v, so it needs a regulator. For years I've used 7805's for 5v supplies, but this device needs something better.

The MCU spends most of it's time in low power idle mode, using less than 2mA, but 'wakes up' about 12 times per day, each time for 1 minute.
During that minute the 12v supplies about 150mA for the rest of the circuit, mostly big relays and lights.
For the remaining 98% of the time the biggest drain is the power consumption of the the 5v regulator. I think a 7805 uses about 5mA.

There is not much I can do to reduce the current consumption during the busy time, but there's lots I can do in the quiet time.

Can anyone recommend a 5v regulator with very low quiescent current ?

Thanks,

Pippin