I have locked myself out of the flat i used to rent so many times, that every time i walked into letting agents office they would just hand the spare key to me without asking.
I locked myself out on 27th of december 2006... Realized it as soon as i closed the door behind me. (That's what i used to do - shut the door, and then check if i had the keys with me ) Phoned my brand new boyfriend (been together for a month), he said he wasn't far away, so we met in the city, went for coffee and then walked to the office to get the spare key. Office was closed.
I spent a night at his place, next day we went back to the office, it was again closed and this time there was a note there that during christmas period opening hours are 10-12. As you can guess, we got there just after 12 . I phoned their emergency number - they told me to get a locksmith.
My flat was on the first floor and i've left the kitchen window open! We went into the back garden (it was never ever used, almost inaccessible and full of crazy cats), my brave boyfriend tried to climb up the wall but failed, so we then drove to his workplace (nobody was working there, but thankfully he's got all the keys to get in whenever he wants ), borrowed a ladder, went back, and he climbed up to the kitchen window, got in, fell into the sink and broke a glass (i forgave him ), and got my keys!
The thing i regret most is not taking a picture of his legs dangling out of the kitchen window! And i had the camera with me!
(Yes, it's possible to write an essay on locking yourself out )