Ergonomic Screensavers?

trance9 sent this submission in: "Where can I find an ergonomic screensaver? Most screensavers lock the screen when you don't type enough. I want one that locks the screen when I type too much. After 10 minutes of non-stop typing, it should let me know it's time for a break. If I keep going for another 5 minutes, it should insist. EMACS has a mode like this, but I don't do everything through EMACS--I think it should really be done by either the window manager, or some X add on. Any ideas?" Interesting! With more and more of us spending time in front of our monitors, would something like this really help out with eye-strain in the long run?