Was trying out Navigation while in my car. Battery had about 30% charge when I left the house. Had GPS on, of course. Droid X was not plugged in, sitting in shade on passenger seat. After about 15 to 20 minutes, went to pick it up and it was very warm. I could hold it, but warmer than I'd ever felt my Eris. BatteryLife widget showed 125 degree F. Also my battery went from 30% to shutting down within 5 minutes of my picking up the phone. So 20 to 25 minutes of GPS killed it. I've read the DX had a lope sided battery (long start, quick end). Of course this is just my 1st charge, and I did get about 12 hours with heavy use (WiFi, browser, apps, games). I just couldn't keep my hands off it today... The drain isn't bothering me since it was just the 1st full charge, but the heat issue. Has anyone else noticed heat with the GPS on?