You readers are amazingly quick off the mark. Four entries in the joke contest so far — three of them actually printable!
Entry #1
How many members of the Obama household does it take to screw in a light bulb?
— What light bulbs? The house is illumined by the light of his countenance.
Entry #2
Barack Obama’s sitting at a bar when a man comes up to him and says: “Wanna hear a Barack Obama joke?” Obama: “Er, hold on there, buddy — I am Barack Obama.” “Oh. all right then, I’ll tell it in Spanish.”
Entry #3 (For Monty Python fans)
“Knock, knock.”
“Who’s there?”
“Barack Hussein Obama.”
“Barack Hussein Obama who?”
“Barack Hussein Obama Gambolputty de von Ausfern- schplenden- schlitter- crasscrenbon- fried- digger- dingle- dangle- dongle- dungle- burstein- von- knacker- thrasher- apple- banger- horowitz- ticolensic- grander- knotty- spelltinkle- grandlich- grumblemeyer- spelterwasser- kurstlich- himbleeisen- bahnwagen- gutenabend- bitte- ein- nürnburger- bratwustle- gerspurten- mitz- weimache- luber- hundsfut- gumberaber- shönedanker- kalbsfleisch- mittler- aucher von Hautkopft of Ulm.”