We'll i completed my first proper OC this weekend and can deffinatly see the difference 
OC'ed a PowerColor ATI Radeon HD 4670 PCS 1024MB GDDR3
OC'ed to:
GPU @ 800MHz
Memory @ 950MHz
I think i might be able to get the memory a bit higher and the card is still running at a nice temp
Anyway just saying congrats to me
Now to learn how to do the CPU..
Edit: Anyone got any pointers for getting it that wee bit higher? Cheers

OC'ed a PowerColor ATI Radeon HD 4670 PCS 1024MB GDDR3
OC'ed to:
GPU @ 800MHz
Memory @ 950MHz
I think i might be able to get the memory a bit higher and the card is still running at a nice temp

Anyway just saying congrats to me

Edit: Anyone got any pointers for getting it that wee bit higher? Cheers