It's so easy to shrug aside the short story. The weekend comes around and all you want to do is stick your face into a fat novel. ZZ Packer's deeply moving story collection, Drinking Coffee Elsewhere (Riverhead, $24.95), is worth a change of plans. The eight stories are smooth slices of life, whether they capture the throbbing energy of a Baltimore street corner or the fanning spirit of a Pentecostal church (''robin-breasted women would swell their bosoms, inhaling God''). But it's the title story that best showcases Packer's emotional heft. A black girl, a miserable freshman at Yale University, falls for a white girl with weight issues: ''One time I'd told her to shut up about it, that large black women wore their fat like mink coats.'' Their awkward, unconsummated relationship is the stuff of true romance.