Good news for female (and single male) party-goers in Las Vegas - "Ladies Nights" are still legal based on new anti-discrimination legislation.
The Las Vegas Sun has a story about the new law that makes it illegal to discriminate based on gender, but allows establishments to "offer differential pricing, discounted pricing or special offers based on sex to promote or market the place of public accommodation."
This is key for Las Vegas nightclubs, which frequently offer free or reduced cover charges for female guests.