Have you pulled the battery and tried to reboot afterward?
There might be a way to factory reset it from the bootloader, but I'm not really knowledgeable of your device.
Let me see if I can dig something up.
EDIT:
If you hold the volume up and volume down buttons, then press and hold the power button all at the same time, it should vibrate. A screen "should" appear asking if you would like to reset, or something along those lines. If you select yes, it will wipe the phone clean and reset everything.
If you have any info in the phone you're trying to save, this will wipe it out. I don't know any thing else to try to get the phone booted at this time.
