I had the power go out on me too, the dead silence of my tanks woke me up. Odd thing is that it was almost an hour exactly between the power going out and coming back on.
As far as the battery powered air pupms, you can get cheep ones that only come on when the power goes out. I think I picked up two of them from Petsmart for like $15. But of course I don't have them hooked up.