Up until recently i’ve been running on (My Hardware Page) but with only 512MB GeIL Value PC3200 (single module).
I’m just waiting till i get some extra little bit of cash through and i’ve saved enough to get the PC4400 modules i wanted from OCZ.
Although cash isn’t short, i like to make sure im not spending cash that i might need in an emergency :), so in aid of making the right memory choice i decided to ring round some friends, a friend who runs a computer shop locally had some in one of his computers (512MB (2x256MB) OCZ Gold LE PC4400) so i went and borrowed it off him for a day, i stuck it in my machine and boy - it made a big difference, which was suprising because the speed of my machine is far from slow as it was!
Anyway with my new cooling and everything i thought i’d try and see what overclock i could get 
I managed to clock to 2.5Ghz, then to 2.55Ghz before i decided to stop as it wasn’t my memory and realistically i wanted like all overclockers should do.. to overclock very carefully - in small increments
at 2.55Ghz i ran Prime95 and 3Dmark01 (looped) and temperatures reached no higher than 43C 
(currently 2.33Ghz on PC3200 - 37-38C)
So hopefully.. in 2 weeks i’ll have my memory and stick it back on F@H with a good overclock - although i doubt i’ll ever catch up with the “bigger boys” 
even NF is almost a good 800 points ahead of me now due to my break from F@H.. (although with my occasional WU being completed by my brothers AMD Duron.)