Throwing 250-300 mhash/s
Is that with a HD 5850 ?
yes, I'd either be mining or doing other stuff so overall electrical usage is negligible.
My HD5850 started stock at 260mh/s and is now running at 391mh/s

Oc it !
I alternate between BTC and LTC mining; so an OC for one would not be ideal for the other.
That aside, I'm waiting to see what magic AMD brings for HD8000/9000 [whatever they call it] =)