I upgraded my PC this evening, going from an AMD Athlon XP 1600 to an Athlon XP 3000 (333). I also replaced my PC2100 RAM with PC3200. The speed increase is noticeable, especially when I ran Sims 2
Kristin predicted that this was going to turn into an all-night battle between man and machine (as many of my upgrades seemed to become in years past), but everything went smoothly (so far).
The next items to upgrade will be RAM (add another 512 to go to 1 GB) and hard drive (add a 160 GB SATA drive or larger). That should tide me over for a little while.