Locks that work

I think I acknowledged that my question was slightly opposed to the way this thread normally runs.

Locks are a compromise between security and utility.

What utility do you want, and what level of security are you prepared to give up.

This is the prefect thread for the question, as this is where all the experts hang out.

Tiswas is thinking on the right lines.

I want maximum utility - ie exceptionally small, exceptionally light, fairly long and flexible. In terms of security I only need something to stop someone picking up one or more unlocked bike(s) from outside a country pub (or similar) in case me and my friends aren't concentrating.

Basically a road bike equivalent of the old town bike wheel locks.

Maybe I should have posted the question in any question answered, but this seemed to make sense.