Sometimes when riding at night it seems that many of the cyclists are guys who have lost their licences for DUI and are on bikes instead. So I wonder how big the market is for Alcoho-Lock, a bike lock with a breathalyzer built in. The cyclist blows into the hole on the lock (which might be an interesting test of sobriety right there, if it is in the middle of a crowded bike rack) and it roughly determines the amount of alcohol on the cyclist's breath.
But interestingly, it doesn't just automatically unlock. Instead, it sends a message via smartphone to a pre-registered spouse or mom or whatever, who then has the option of yelling at you and telling you to walk for all she cares, or unlocking the bike remotely so that you get what you deserve riding drunk. I can imagine some of the conversations.
I am not certain that drunk cyclists are that much of a danger to anyone but themselves, but if you don't, as Gizmodo put it, mind someone meddling with your pedalling, this could be useful. What do you think?