Need help troubleshooting - MacBook Pro startup issue?

For some reason I can’t get my MacBook Pro to startup. All I get is a screen with the apple logo and a spinning gear. I’ve reset the NVRAM and the SMC. I’ve also done the extended apple hardware test, ran fsck from single-user mode, and run disk utility and found no hardware problems whatsoever. It won’t boot in safe mode and I still can’t get past the apple logo/spinning gear screen. I’ve spent lots of time searching google for info and tried a lot of things without any luck. Since the HD seems to be fine I’m hoping I won’t lose everything, but I’m running out of ideas short of taking it in to the Apple store tomorrow (which, unfortunately, is an hour away). Any help or suggestions would be greatly appreciated.

I just bought this MacBook Pro last August, so it’s running the latest OS (10.6.7 I think).