Bike security camping

[kynikos]

A length of string attached to the bikes and the other to your big toe when settled in for the night.

...makes it difficult to chase after 'em as your balance is severely affected by the severing of your big toe as they make their escape

 

[Cycleops]

Yeah but on the plus side, no batteries keys or wires to worry about and low cost and low tech.
I'd say it's just about the perfect solution.