Desktop annoyances - network lag

Some things always feel uncomfortable about my desktop usage, even when I change solutions - KDE, GNOME, XFCE, all the way down to evilwm and beyond, to the console. I want to pin these problems down, in order to address them. First I want to focus on network lag. Take email as an example. One of the biggest changes I made to my use of email a few years ago was to store all my email on an IMAP server, so that I can access it from any computer I happen to be using....