Smart cycle lock might be worth a look

[Mobileman]

Just read this on Engadget looks pretty good but will it work if it's twatted with a hammer ??

http://www.engadget.com/2013/10/29/l...art-bike-lock/

Lock8 thwarts every kind of bike thief through GPS and smart alarms (video)
By Jon Fingas posted Oct 29, 2013 at 9:50 PM
Many attempts at smarter bike locks, well, aren't -- they won't last long against thieves with the right tools. If Lock8's new security device ships, however, those ne'er-do-wells won't have it so easy. The smartphone-controlled lock includes the GPS tracking you'd hope for, but it also includes sensors that trigger alarms and notifications for just about any kind of theft attempt. A smart cable warns if someone tries a bolt cutter; an accelerometer can detect drills and saws, and there's even a temperature sensor to fend off blowtorches. Owners can rent their rides, too. Lock8 is crowdfunding the technology, with pledges starting at £69 ($111) for those who want a lock and six months of free GPS service. If the company meets its £50,000 ($80,340) goal, bikes worldwide should be much safer by May 2014.

[BertRoot]

Erm the thing sits where your rear rotor is for a disc brake setup.

[keyser666]

Just got my bike back after it has been stolen and am serious looking into these, looks far better http://ridehelios.com/