Chicago ? What does an accomplished man of the world get for his 66th birthday?

Well, President-elect Barack Obama already gave Joe Biden the vice presidency. So, for his birthday, Obama gave Biden two ball caps and a rendition of the birthday song.

Biden’s birthday is today, but Obama surprised his No. 2 after their weekly lunch Wednesday at the transition office in Chicago. According to staff, Obama presented Biden — a Delaware senator with decades of foreign policy experience — with a dozen cupcakes decorated with candles and teased, “You’re 12 years old!”

Staff reported that Biden laughed at his boss’s joke. He responded: “Maybe in dog years!”