If you are a mutt user like me, and you are running Debian GNU/Linux or even Ubuntu, I highly recommend apt-get installing 'mutt-patched'. One of improvements it brings is a small 'folder list' down the left hand side of your terminal window. You can configure this folder list to monitor subfolders for new mail. This is a boon if you have procmail filters which direct different types of mail (e.g. mailing lists, work mail, etc) into different subfolders. In essence it's gmail-like functionality, or any modern GUI mailer for that matter, but for the console user. I'm excited to be joining the 21st century!
Info on configuring this setup can be found in /usr/share/doc/mutt-patched/examples/sidebar.muttrc
Have fun!