Here's a tip about filters in Gmail.
I'm migrating Gmail -> Apps using POP and found it pretty inconvenient when all (auto-)labels were gone.
As many Gmail users do, I use filters which automatically labels incoming email.
Now: Google Labs to the rescue!
I enabled this on both my accounts:
by Luke B, Slava C, and the Data Liberation team
Export your mail filters as a file: back them up, share them, or save them before deleting so you can restore them later. Import one of these files to quickly add or restore filters. These options become available under Settings/Filters when you enable this Lab."
So. Easy. Just export all filters and then import them into your new account!