We just received a link leading to an AMD-sponsored YouTube channel, showing an HD video how Brian McLachlan [alias chew*] overclocked Phenom II 955 and DDR3 memory. You can see the HD video here and a conventional SD video here.
What caught our attention in the video was the fact that Brian didn’t take the usual route of slapping a LN2 pot and pouring Liquid-nitrogen from the word go. Chew* used AMD Phenom II 955 processor, GigaByte 790FX-based motherboards [MA790FXT-UD5P], Corsair DDR3-1866 memory, ATI Radeon HD 4850 and 4890 graphics cards in single and Crossfire mode. In this video, chew* posted 4515 MHz CPU-Z using an air cooler, 5217 MHz CPU-Z score using Dry Ice and 6405 MHz using Liquid Nitrogen.
Personally, I am not very interested in seeing validation screenshots, even though I understand their point. I was always an stable system overclocker – my CPUs have to pass a 24 hour Linpack run in order to be called stable. Chew published so called "extreme stability" results as well, reaching 4070 MHz on air, 4717 MHz on Dry Ice and 5751 MHz using LN2. Playing a game on 5.7 GHz would be an interesting experience, if there wasn’t for continuous need to pour the LN2 into the pot. DDR3 memory was clocked to 1443 MHz using 5-5-5-15 latency, while top score for CAS6 latency was 1636 MHz [6-6-6-16].
Of course, all of the overclocking effort would not pay off if there weren’t for some results: #2 3DMark06 with a single HD4890 – 23883 3DMarks, #1 with dual HD4850  and dual HD4890 . All in all, good to see mainstream companies embracing their own enthusiasts, even though everything that you saw there effectively voided warranty ;-)