Did some experimenting with overclocking my computer today. It's running an Intel Core 2 Duo E6420 which runs at 2.1GHz by default (bus speed of 266MHz with x8 multiplier). Upped the bus speed to 299MHz and now it's running at 2.4GHz. My Windows Experience Index for my processor went from 5.1 to 5.3. Idle temperature is now ~50 degrees Celsius using the stock cooler. Hopefully it'll be stable when playing COD4 and COH!
These processors are very easy to overclock and squeeze a little extra performance out of them. Now if only we weren't saving to move house (not to mention some wedding I've got to go to) I could justify an upgrade to one of those nice Core 2 Quad Q6600s!