Why is my MacBook stuck on the blue screen during booting?

My system started having problems last night, when my fan stopped running under OS-X. I restarted, and booted off a live linux CD, and the fan worked. So I held down the power button to go back to OS-X. The booting got stuck on a blue screen. I've tried rebooting in safe mode (goes through the safe mode and straight to the blue screen), resetting PRAM, going into the single user boot and using the fsck command to check my hard drive (it's ok), and anything else I could find. I do not have an installation disk, or I would try live verification, but that isn't an option. My computer will boot off the live linux CD, though it says there is a kernel issue, and only boots into a command line interface. What is going on?

Thank you for your responses. I'm currently in New Zealand, so it's a little hard to get Apple supplies, but I've got a friend sending me an OS-X disk. And in the meantime, I managed to firewire my way in from a pc running linux, and get my files off. Then I formatted the drive and put linux mint on it.