filters or smart folders?

Hi,
I've been using gmail since it was in beta all those long years ago and as we all have in the past swear to it. I recently made the switch to MobileMe for my calendar and contact sync. However I am very displeased with the email service. I have over 50 emails coming in on a given day and with gmail I have them filtered out into different folders which significantly cleans up my inbox. How can I do this with MobileMe? In the web view I see how I can create a folder but not apply any rules to it. Thanks