Using updates via her Twitter and Tweets from top 40 radio station Z100, the pop singer is hiding somewhere in the city and will "personally hand you" two frontrow tickets to the fans that find for the show tonight.
The game started last night and so far, the hints so far include that she's in Manhattan, at an outdoor spot below 60th Street and above 20th Street and is a "guilty pleasure." Apparently there is a clown that you're supposed to tell "I seek Britney" (as opposed to "Amy").
This stunt comes with the kick-off of the second leg of her North American "Circus" tour. She played two shows in Ontario at the end of last week and appeared on David Letterman last Tuesday, in a bikini and helping issue the daily Top 10 List.
UPDATE: Winners find Britney and her clown outside of the M&M store in Times Square. Check out the pic.