Since you can't even turn you machine on - and you don't say if you're running Lion or Mountain Lion which both have Recovery partitions - it's impossible to diagnose your problem over the Internet. If you are running Lion or Mountain Lion, see if you can boot into the Recovery partition by holding down the Command and R keys while booting. When there (if you can get there) use Disk Utility to verify and, if needed, repair your hard drive.
If you're not having any luck with the Recovery partition, boot with the installation disc that came with your MacBook Pro and try running Disk Utility from it.
If you cannot do anything above, try running the Apple Hardware Test (if you can). If you're able to run the test, note any errors that might appear.
If all of this fails, you're just going to have to break down and get your machine to your local Apple Store or an AASP. Machine may be fried.