Friends’ Rachel may have grown hers out, but the bob is still getting serious TV hair-play. Sela Ward recently revealed a smart, layered cut on Once and Again, and Buffy the Vampire Slayer’s Sarah Michelle Gellar hacked off her Rapunzel tresses in a post-Spike panic attack during the show’s Jan. 8 episode. Next on the chopping block? Sex and the City hair-oine Sarah Jessica Parker, whose new tousled bob will be seen soon — but probably without any plot-line to-do. Says an HBO rep: ”It’s really no big deal.” For Aidan’s sake, let’s hope Mr. Big agrees.