To imitate Elvis, you put on a leather jacket, comb up your hair and shake your hips. To imitate Chuck Berry, you strap on a guitar and practice your duckwalk. But imitating Bob Dylan takes no practice whatsoever -- just a whiny voice, a wheezy harmonica, a rough notion of rhythm guitar and a set of old denims. Those modest capacities will be celebrated next Wednesday night in Nietzsche's, 248 Allen St., at the Second Annual Bob Dylan Impersonators Contest. Prizes of cash and objects of musical interest will go to the best soundalike, best lookalike, best approximation of Dylan's harmonica style, best parody of a Dylan song, best interpretation of a Dylan song and best original song in Dylan's style. Judges will include Night-Life magazine's Kevin Hosey, Joann Sheridan of J-2 Productions, alternative rock expert Marty Boratin, WEBR's Al Wallack and bandleader Jamie Moses.