For prior versions, I was able to download and extract the new one, and then move the .dat files over to the corresponding folders.... that way, when I opened the wallet client, it didn't have to re-download the entire blockchain and everything worked fine.

So my question with 0.8.1 is whether I can do the same as before, or is there something unique about it that I should let it reload the blockchain and just import my wallet and addresses?

Thanks in advance. 

oh, and a side thought.... any suggestions on good 'how-to' guides and specs for newbies for setting up a USB wallet?  Thanks.