For those of us on there (whether you've been stalked by fuckin' Peytros or not):

1) Scroll to the bottom of your Facebook page.
2) On the bottom left corner, click English: US.
3) When the language selection appears, click English: Pirate.
4) Yarrr!

The level of detail at which this was implemented is pretty impressive. Hint: try hiding the annoying ads after turning it on.

lol, nice

lol, nice find. Now I be off t' blabber t' mi mates!

[edit]

Arrr, it be changing the facebook language used by my mobile too! Arrr!

Yarr, thar be three scratches 'pon the wood!