Conan O'Brien to Appear on 'How I Met Your Mother' (Video)

Conan O'Brien
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"You worked tirelessly for four years to earn the diploma you will be receiving this weekend. ... And Dartmouth is giving me the same degree for interviewing the fourth lead in 'Twilight.' Deal with it."

Conan O'Brien on How I Met Your Mother?

It's not a joke. On last night's episode of TBS' Conan, guest Neil Patrick Harris -- touting his upcoming films The Best and the Brightest and The Smurfs -- revealed that O'Brien had bid on a walk-on role on HIMYM during a charity event at Ojai earlier this year.

If and when O'Brien appears on the CBS comedy, the question becomes how he'll be used as an extra. After all, O'Brien stands out.

"Normally it's just in the bar scenes, we just sit the person over our shoulders so they can say, 'Hey look, it's me,' " Harris said of the prize.

"The producers were saying, 'We'll actually write you in as a character,' " O'Brien said. "But I think it's much funnier if I'm just in the bar in the background."

Check it out: