Well - was watching tv - phone sitting table beside me. I picked it up - hit power button to wake it up - nothing. Though maybe it turned off or something. Held power button -- nothing. Pulled battery - nothing. Luckily i read on here somewhere about keeping battery out for 5 minutes. Did that - and it booted fine. No idea why it did that - hope that is not something that will happen again.
Also - i read this may be indicative of a bad extended battery. Some have said that Verizon was having issues with the first batch of them and are replacing them.
Anybody else have this happen? Any idea of cause?