This Friday, September 19th, is "International talk like a Pirate" day. This historic holiday was invented by John Baur (Ol' Chumbucket) and Mark Summers (Cap'n Slappy), and popularized by humor columnist Dave Barry.
Celebrate by wearing an eyepatch, donning a peg leg, or teaching your parrot to say "Keelhaul! Keelhaul!". I don't recommend taking a hook, sword, pistol, or cat o' nine tails to school, though. The establishment frowns on this sort of thing and if it gets out that Mr Spanky planted this thought in your Phun-filled mind then I'll never hear the end of it.
If you're having trouble with your "Arrr!", "Ye scurvy bilge rat!", or "Swab the poopdeck, me hearty!" I recommend that you get professional help. The folks over at Wikihow have an extensive tutorial that is mandatory if you want to avoid embarrassment.
If you're a fan of Instant Messaging, the folks over at Meebo will make things easy for you. Simply log in to your IM account through Meebo and then type "pirateon" to start. It will handily translate your banal messages into fearsome Pirate Speak.
Remember to growl and scowl often!
P.S. Post-it note cartoon by Doug Savage's brilliant Savage Chickens.