I'll second the X31 - I've had an X21, X22, and now and X31. In some ways, I like the X22 better (just got the X31, so I'm not used to it yet), but for sound, the X31 is awesome - very quiet! Can barely hear the drive spin up and down like I can on the X22.
I've only got 256 MB onboard right now, so it's not screaming fast in XP - lots of paging. I'm going to get another 512 MB and see how much speed it gains.
The 4200 RPM drive is pretty slow, however. I'm tempted to get a 5400 or 7200 RPM drive... might have a 40 GB drive for sale soon!

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Reliability is top notch, too. I can't say enough good things about the X-series ThinkPads. Bundled utilities are pretty handy, too.
Desktop full docking stations are going for like $50 on eBay right now - they include both DVI, an ultrabay, 2 more PCMCIA slots, and even a 1/2 PCI slot. Pretty good deal!! They seem to have a fan for the power supply

. I picked one up a few days ago, so I'll see how it sounds. I'd like to get rid of my iDeq that I use just for scanning.
-Dan