"Sup is a console-based email client for people with a lot of email. It supports tagging, very fast full-text search, automatic contact- list management, custom code insertion via a hook system, and more." I'll have to check this out (I'm just using Gmail on the Eee at the moment, and it's not good enough...)

I'm using mutt at the moment, but thought I might as well give this a try. Looks like it's a bit easier to set up and use.

GmailFS provides a mountable Linux filesystem which uses your Gmail account as its storage medium. GmailFS is a Python application and uses the FUSE userland filesystem infrastructure to help provide the filesystem, and libgmail to communicate with Gmail.