Most places will let women in for free generally. If not, getting on a guestlist or getting a guest pass for complimentary entry is not difficult. We try to rationalize it, but it's not exactly fair that men have to pay (even when on a guestlist or with a guest pass) while women do not. I guess across the nation (and probably the world), the women get "pampered" if you will with regard to the nightlife scene...even in the more mundane scenario when men offer a woman a drink. So it's not exactly unique to Vegas. However, does it at all bother you? The truth is, I am so used to it that I would simply go without the nightlife if they charged women at least to the same degree they charge men.