Actually - I have asked the same thing... but considering there is a trade session following - I'm opting for something comfortable and machine-washable. I decided against slinky Vegas black and sequins - so tell your wife (I assume this is who REALLY wants to know... ) - that this "girl" will probably wear something "nicer" than shorts and a T-shirt, but still very casual and comfortable. (probably a dress or skirt... but cotton and summery. NO HEELS! COMFORTABLE! Hope that helps?)

Also - it is getting warm in the desert, isn't it?
What temps are we talking in Las Vegas at the end of May? (daytime? evenings?) You guys hit 100 during the day?