Longest time locked outside was on Friday evening when I met up with another cyclist for a drink and had our bikes locked up outside the shop under a lamp-post. We stayed there for a few (2-3?) hours and needless to say, we where both looking out ready to make a dash since this wasn't the safest of areas to lock up the bikes.

Even though the chance of a bike being stolen is very high, I'm usually more worried about minor theft of items and vandalism which takes seconds to happen, since I always leave the bike in a spot where I can see it.