NEW YORK, NY September 21, 2009 —The countdown has started for President Barack Obama's appearance on the Late Show with David Letterman tonight. This is the seventh TV gig in 48 hours for the president as he tries to bring his message on health care to the nation's living rooms. Eager fans lined up outside the CBS studios for this afternoon's taping. Fernando Duguia is an Obama supporter from Staten Island.

DUGUIA: Really excited, definitely a nice surprise for him to come here and to be part of the show, and also to see what he had to say.

Joanne Morgan didn't know Obama was the guest when she got tickets for tonight's Letterman Show.

MORGAN: I think health care does need to be reformed, however not the way he wants to do it.

CBS will air the Letterman show tonight at 11:35.