To DannyHamilton:

I am another newbie trying to understand some similar things to the OP.  Could you explain a little bit more about the "extranonce" and how it operates?  After doing a few searches in the technical bitcoin Wiki I am still not getting very far.

 As a solo miner, is it possible to predetermine a set of changes to the block header in advance to allow a very fast processor to calculate more than the maximum nonce set (2^32 possibilities) before having to reconnect with the mining client?

Thanks for your help!