I use a 3.0 GHz Core2 Duo, 8 GB RAM, 4-disk RAID5 with a 7800GTX + a 6200. An early Dell 24", an S-IPS HP LP2065 and a piece of junk 19" Sceptre. The only use of the latter is to look at edits with a "what a junky monitor would show". All color corrected with a Huey Pantone.
Linux + GIMP.
I have some Windows software running in wine and vmware. The Canon raw processor (most hated software). And Photoshop mainly for editing in LAB (LAB editing in GIMP doesn't allow you to view real time in real colors, although the G'IMC plugin is 90% there, at least you have sliders and real-time view or curves and click-to-view now).
I have some Wacom tablet or other but I have built a lot of muscle memory with the mouse and it isn't easy to switch.






