go have a look at Gmailer XP, currently only in Nightly builds but its got great potential. It doesn't quite change it to pop3, but u can do everything with Gmail on your computer, read etc. with a clean interface like gmail's. Filters and settings can be changed in it and they will also be affected on the server.
For more information go to ->
http://gmailerxp.sourceforge.net/
From frontpage of site:
GmailerXP is the be-all-end-all utility app for Google's Gmail service. The program allows users to do anything that they can do online, it also combines all the features of the other programs (GML, Gmailto, etc.) The ONLY Gmail app you'll ever need.
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