Back in 2004 during the first months of Facebook, I deleted my account. When I signed up again a few days later, everything was still there with profile picture and everything.
The standard flow for "deleting" your account actually says "deactivate your account", and the fine print is explicit in that everything comes straight back when you log in again.
There's also a hidden link in the support pages somewhere that's supposed to actually delete your account (which is what's linked here)
[Updated: fix year FB was launched]