I was recently setting up my machine and figured I'd try 'mutt', the terminal mail reader. It's a pain to install and isn't great for HTML emails, but it sure is blazing fast and allows me to create custom macros that are really useful. Maybe if I stick with it, it'll be faster than GMail. But then again, after I set up some filters, my volume of email to look at in GMail was pretty low, so the performance advantages of 'mutt' are not as important now. It feels super cool though. We can't underestimate the aesthetic value of cool terminals.
