Pools for local Las Vegans?

I live in Vegas and my family in PA thinks it's very glamorous and thinks we must spend the hot summer days lounging by resort pools. Well, we don't. They're coming to visit and really want to lounge by a resort pool. Where can I take them? Who will allow us to access to the pool without staying in the hotel? Any info would be greatly appreciated. I want to show them a good time without spending a fortune!