Will driving with a blown head gasket damage the car?

Although rare, if it overheats the block could crack. If the coolant and oil mix (keep an eye on the oil condition), it could wipe out the bottom end of the engine. If the cylinder fills with coolant enough and the piston tries to compress the liquid, it could do damage to several parts including twisting the crankshaft. It would be smart to not drive it, but I guess life is all about risks and opportunity costs.

More Information:

I was driving home this afternoon when my car made a terrible noise and was loud. It sounded like it was coming from the engine. When I got home a neighbor( and a mechanic) drove it and said it was a blown gasket. can I drive it until it gets fixed?

I wouldn't drive it until it gets fixed. I might drive it TO get fixed. I am thinking of doing that myself. But it's very serious so don't keep driving it around (if you even can).

it's a nice reason to start hitch-hiking...