The bars generally have updated schedules on their websites:

http://www.toolshed-ps.com
http://www.thebarracksbar.com/home.html
http://www.huntersnightclubs.com

You may want to check the local gay papers in advance:

http://www.desertdailyguide.com
http://www.psbottomline.com

The Desert Daily Guide generally has events listed by date, although it looks like the site is not updated with the current edition. Also, ToolShed Bingo can be fun. I have won several T-Shirts and tchochkes through the years, along with a couple, um, adult un-mentionables.