Crazy sound on MBP?

I have a MBP about 2 yrs old - still under Apple Care but the nearest Apple store is about 150 miles away! Mas OS X (with software updates current through today!) Version 10.6.2, Processor: 2.4 GHZ Intel Core 2 Duo, Memory: 2 GB 667 MHZ DDR2 SDRAM. Twice today, once on the AC power adapter, and just now on battery (with 87% Charge) my cursor locked up and nothing would get the computer going again except to remove the battery. I could not "Force Quit". The second occurrence, on battery power, the computer was making a noise that sounded like a fog horn beeping three shorts times with a short interval between repeating the three beeps over and over again. I've never heard that. I removed the battery and re-booted and everything seems OK.
Has anyone ever had this happen - and/or - any ideas on what's going on?
Thanks, Bill
Wilmington, NC

I think your harddrive is failing. To make sure open Disk Utility and check the S.M.A.R.T status of your HD and click on Verify Disk to make sure.

I also suggest you go to the nearest Apple Authorized Service Provider if you can't go to the Apple store.

to find the nearest AASP click here:
Apple - Service Provider Locator

I hope this helps you!