I too have MBP but have not yet experienced any annoying fan noise thus far. Mine is 2 yo and my wife's MPB is new.

In your situation, I would do the following:
1. Check if your OS/firmware is updated. In certain cases, this might provide a quick fix. Are you using Leopard or Snow L?
2. MBP is designed with very minimal exhaust vents other than those on the speakers. If you think that those are clogged, try and purchase one of those compressed air cannisters and give it a good burst to clean it out of dirt and dust.
3. I would not recommend you to open up your MBP as it might void your warranty. But if you must, try and see if the fans are working normally. It's possible one is busted and the other is assuming the workload.
4. Get one of those laptop cooling gizmos. It just might do the trick.
5. If your MBP is still within warranty, nothing beats having a Mac Genius troubleshoot it.

Hope this helps. Let us know if you have found a solution.