Looks like sort of slim pickings.
http://www.wififreespot.com/nev.html

I use a "pay-as-you-go" dial up service when I travel - Budget Dialup - you just buy a block of time and then use it as you need it. I don't think the hours expire for a year. I have found that they have local numbers in most of the places I have stayed except for some of the small towns in the midwest. Although, going to Krispy Kreme to have a snack and read my email doesn't sound too bad....

http://www.budgetdialup.com/default.htm