PDO's getting more and more out of date as the webmaster lets it rot without attention. You can check http://www.txdps.state.tx.us/adminis...eciprocity.htm for the current list. As such, you're good to conceal on a Texas CHP in New Mexico and Alabama. When you're in Nevada, you'll be good to OC in a car or on foot everywhere in the state except Boulder City and North Las Vegas (and having visited there myself, there'd be little to no reason to stop in either of those places).
Edit - You'll probably be good to conceal in Nevada by December as well. Nevada just passed reciprocity legislation for the first time and it goes into effect on October 1st; I'd be really surprised if Texas didn't make the cut.