Burning phone in the USA

I will be doing several festivals in the USA this summer (Coachella, Sasquatch and Burning Man) and a phone is pretty much a necessity for arranging entrance into these festivals with friend from across the country. Can anyone recommend a good plan for buying a cheap phone and a pay as you go plan. Even just having a text message plan would suffice. I basically want a burner, a phone that I can throw away after festival season. Currently I have a Blackberry Curve which is paid for by work and am waiting out until the Motorola X-Phone is announce to buy a new personal phone (I had the Galaxy Nexus and Sold it for the Nexus 4 and then got screwed over with the delays, don't want one now)

So my options are this:

1) A burner phone with credit and use that

2) Buy a SIM that works on 850/1900 MHz

What is the easiest option? I'll only have a few hours in LA to get this all sorted before the first festival which is Coachella. My blackberry is basically a dumb phone so I wouldn't want or need data on it.