The Reliable Source

· Cynthia Nixon touring the Spy Museum Sunday afternoon with her girlfriend and two young children. The erstwhile star of "Sex and the City" (she was the redhead) wore a long black coat and trekked through with an ordinary mob of tourists. Why was Nixon in D.C.? "Because," said her publicist. That's right: Just "because."

· Ben Bernanke trailing his wife and daughter Sunday through the aisles of Whole Foods on P Street. The Fed chair, dressed down in regular-guy attire (baggy khakis, hiking boots, sweatshirt), was recognized by at least one shopper. After paying for his groceries, Bernanke got a helping hand loading them into a black SUV from his Secret Service detail. Always handy on snowy days!

LOVE, ETC.

· Daddy, Oh : Tom Brady broke his silence yesterday about ex-girlfriend Bridget Moynahan's weekend announcement that she is three months' pregnant with his child. "Tom and his family are excited about the pregnancy," his agent told the Associated Press. The couple broke up in December after a three-year relationship; the New England Patriots quarterback is now dating supermodel Gisele Bundchen.

THIS JUST IN . . .

· Britney Spears's surprise head-shaving was apparently neither the fashion statement nor edgy punk gesture we might have hoped for -- but a genuine cry for help. The pop starlet, 25, checked into an unnamed L.A. rehab clinic yesterday, her rep told reporters. Manager Larry Rudolph would not say what the singer is being treated for. Several publications reported that she briefly checked in and out of a rehab center last week before her mysterious Friday night trip to a Los Angeles hair salon where she grabbed a pair of clippers and bared her skull.