Don't tell Tim in San Jose...

Actually, are you referring to the key to your gasoline tank cap? In
all of my Vanagons (syncros mind you) this is the same as the ignition
key. Replacement caps (probably what Tim has) can be turned with a
screwdriver if they didn't rekey it. The originals can't be (at least
not without destroying the mechanism.)

I assume it is also possible to have a different key for the gas cap
then the ignition. But I always sort of liked the fact that I'll find
it difficult to drive away if I don't put the cap back on.