Stolen bikes

Was it on this thread or somewhere else that I read about discreetly sticking a tiny luggage lock on one of the chainlinks? That way if they get through the locks and try to ride away at least they'll fall off (and hopefully get injured). Would work best for those situations where you've locked your bike is in sight but not at arm's length.

The Xena Alarm would do the same. It locks around the chainring, so even if the thief isn't put off by the alarm going off, they wouldn't be able to ride the bike. £35 well spent.