On the Ghostbar's website it says "Stylish nightlife attire required, NO athletic wear, shorts, tennis shoes, baseball caps, or flip flops." The VooDoo Lounge's website didn't say anything about the dress code, but I think most clubs are this way, I cannot remember whether or not I saw anyone wearing jeans when I was there. Another place my GF and I liked was Minus 5 Ice Bar at Mandalay Bay (there is also one in the Monte Carlo). Everything in the place is made of ice, tables, seats, glasses, bar, sculptures, etc.