Establishing a new brain wallet.
Satisfied with my pass-phrase, I boot-up an Ubuntu live-cd, switch to private-mode browsing, navigate over to bitaddress.org, physically disconnect from the network, generate a private key from my pass-phrase, record the bitcoin address, and then pull the power cord.
While coming up with my pass-phrase (derived from a painting above my desk, including a proper name and a number), I remembered this xkcd comic: http://xkcd.com/936/
I wondered if anyone had established an address with the punchline "correct horse battery staple" and I knew the answer before I even checked
"correct horse battery staple" -> C4BBCB1FBEC99D65BF59D85C8CB62EE2DB963F0FE106F483D9AFA73BD4E39A8A
Any other common phrases warrant a look?