I am new to the Migration Assistant app. I'm trying to prepare my macbook for its migration to the new 27 iMac quad core. However, I don't want all the crap from the original macbook to come along with it. (old pref files, certain apps, caches, etc.) What can I do in advance, or rather, what should I do in advance to to prepare for the transition. Any helpful hints, successes, or things that have worked well would be greatly appreciated.