Help, won't boot up

Macbook pro running OS 10.6.2

I was browsing the internet and the screen froze. All that was happening was the rainbow spiral. I did a hard shut down.

Powered back up. For the past 25 minutes all the computer is showing is a clockwise black spiral on the first screen before the blue screen.

What can I do next?

Thanks.

Could be anything. Not enough information to make a diagnosis.

For starters, boot from your original system DVD and see if the machine can boot up that way. If so, can you see your hard drive anywhere?

Just did a PRAM and NVRAM reset (command-option-P-R).

I'll look for the sys disk.

Found sys disk.

Inserted and pressed "C" key.

Still only see the first gray screen (with apple logo and clockwise spiral).