Main thing to remember would be to avoid feeding blocks, they would just make the water go cloudy and horrible while you were away.
Next thing to do would be to try and find a battery powered air pump, and rig it up to as big a battery as possible (like if the pump takes AAA's, use wires and tape to connect D's.. The compressed air idea sounds good too, if it's just compressed air.
Then if possible attach any available sponge filter to the air pump, and put some mature filter media underneath it or somehow wedge it onto the filter.
I don't know if you have live plants, but if you do, try to reposition the tank somewhere where it will get sunlight from the window.
If you don't have live plants, it would be a good idea to get some fast growing ones if possible, and reposition the tank.
Obviously having the tank next to a window isn't the best idea if the house is hit bad, but if that happens you'll probably have bigger problems anyway.
If you can get live plants growing, they will help the water a lot in the absence of the filter, and give the fish something to nibble on.
Oh and unfortunately, your going to have to be prepared to come back to a tank full of fish that needs cycled again - the filter bacteria are all going to die without food while your away.