Friends of ours are getting married in Las Vegas in October. Invitation says something along the lines of smart casual, and I know for sure that it's not going to be formal. But that still kinda leaves me stumped. I want to make some sort of effort but not look out of place, and then of course there's the eternal Vegas dilemma of warm outside, frigid a/c inside. There will be a ceremony, and then a nice dinner with everyone afterwards. Any thoughts?