Hey Nod,
It's best to stick with one pool for 2 days and keep running ive the 48 hour 2 day period to get an exact idea.
Best bet is Slush's pool -
http://mining.bitcoin.cz it's been good to us, or DeepBit, try both for 48 hours at a time, keep the mining machine running constant as you can for the 48 period. Post back and let us know the results, if you can PM me in here let me know your experience man, if you can??
Thanks heaps, Slush's is going well for me, Haven't tried deepbit myself, friends have and said it is ok also.
It would be interesting to see the difference now with current difficulty.
Thanks, much appreciated!