A little research shows these things are junk. You bring up a good topic though. I'm going to buy something like this in a 5' length, then it's long enough to run through both bindings and you aren't going to cut it with a wire cutter or snap the lock.
Kryptonite KryptoFlex 1007 Cable - 7' at REI.com
I'll lock it to the rack in the morning where I usually stop to eat/drink that way I'm not carrying it all day. I'll carry the little burton one in my pocket in case I stop anywhere else.