Most of my time sitting in front if this machine is thinking time: planning, researching, writing. Unless Intel or AMD come out with a chip that allows me to put out finished documents at 1,000 words per minute or so, no faster machine is going to improve my productivity over this PIII-600 war horse.
I admit that somewhere in back of my mind I've been kind of thinking of getting a new machine at the end of the year, though really trying to resist the temptation. Now I'm just going to take a walk over to Staples and pick up a copy of Norton Utilities. If it tunes things up as nicely as POR says, I'll hold off on upgrading until it's really worthwhile for me.