The only nice thing I can say about Vegas is that I never had trouble walking up to a business from the sidewalk, asking for a cup of water and getting it for free. I think they didn't want me dropping dead from the heat right in front of them, that'd probably be bad for business.

Granted, that was 15 years ago and things may have changed. If I were made to go back, I'd bring one, maybe two, reusable water bottles and count on filling it myself in my hotel room.