Regular readers of Vanna White's blog probably know she was a vowel for Halloween, but not an "e," the most popular vowel in the language. And really, it was just a lousy T-shirt costume — not at all as interesting as the video about her cat doing tricks in the video above. But dedicated Wheel watchers who want to compete for a chance to appear on the show (on the air for 35 years now) and buy a vowel from the world's most famous letter-turner can apply when the Wheelmobile rolls into Harrah's this weekend and next (1 p.m.- 5 p.m. Nov. 6-7 & 13-14). The roving audition bus will park on Fulton Street and prospective contestants can apply for one of three slots each day to impress the judges. (Hint: spelling and knowledge of common phrases may help on the show, but the casting judges are looking for players who are "energetic, enthusiastic and fun.") Successful applicants will appear on episodes to be taped in New Orleans during three weeks in April. (And just to be clear: Vanna will be in town in April, not the Wheelmobile event this weekend.) Auditions will be in Harrah's Theater for three days and outside on Fulton Street on Saturday, Nov. 13. Contestants must be at least 21 years old.