Nowadays I just use the "screen off after X minutes of inactivity" feature. As far as I'm aware, I don't think XP-style screensavers are needed anymore (unless you happen to have a plasma screen for a monitor), but it shouldn't hurt anything to still use one. I just have the screen go off because if I'm not at my computer anyway, I'm not going to be there to see a cool screensaver, so might as well save a bit of power instead. If I have world community grid running, I will sometimes enable that screensaver, but that's the only exception