Do you work in an environment where you bounce through a bunch of firewalls? Do you hang out on idle ssh connections that often times get dropped after a certain amount of idle time? I do and it has always annoyed me. To the point that once I connect to a box that I will be coming back to, I will run top and move on. Well, not anymore. You can set your SSH client to automatically send a bit of data over your connection every X seconds.