Sex and the City has found just the guy to investigate the show's sextraterrestrials: David Duchovny. The former

X-Files G-man has signed on for a guest stint on the Emmy-winning comedy, an HBO rep confirms. Might Duchovny be playing the much-buzzed-about new love interest for Carrie (Sarah Jessica Parker)? HBO isn't saying, although exec producer Michael Patrick King recently told TV Guide Online that the pivotal role had in fact been cast. "It's a big name," he teased, adding that Jack Berger's successor will pose stiff competition for Mr. Big (Chris Noth) as the series heads towards its climax in early 2004. "Why would we bring in a major name if [Big] was already [the clear winner]?" I've got a better question: Considering Aidan and Steve are partners in a bar, how come Carrie didn't already know that her ex-love had become a daddy?