A quick and easy question for this crew, I'm sure. I just added my yahoo email to my Tour and while I get my yahoo emails they mix with my business emails. I do have 2 icons one for Business and one for Yahoo .. it would be nice to keep them apart.
So you have a Messages folder, and then you have the individual email account folders. Hide the Messages folder, and then just use the individual folders depending on which account you want. That will keep them pretty separate.