Obviously atman is not following this thread at the moment, but I'll throw in the question anyway, to be dealt with later and/or in case someone else has an experience: What about getting the lock through as a carry-on? I'd like to carry both a U-lock and a cable lock with the bike. Could these put the whole undertaking into risk? My personal experience is coming up in less than 2 weeks. I had already a simple Topeak tool with hex bits taken away from me, but that was outside of the US.
I'd think that worst case is they would confiscate the lock on the grounds that it could be used as a bludgeoning device. I don't see how it would affect the bike getting through.
If you are checking a bag, just pop the lock in there.