Some of the bike lockers under the Town Hall building in the Sydney CBD. These are the best lockers I've ever used. They stuck them in a few spots where you couldn't park cars (and most parking lots have quite a few of these), and everyone who wanted to use them was issued with a padlock. It was first come, first served from that point on. If there were 20 lockers and you were the 21st to arrive, you had to lock your bike up the old fashioned way. That was a good incentive to get into work early.
I like lockers because no bastard can steal bits off your bike. You can leave your pump, bike computer, front wheel etc attached and know that all those bits will be there when you get back.