I'm shopping around for a barebones laptop onto which I would like to load the linux kernel. Does anyone have any advice as per what I might want to look for? Is there hardware which is ideal for Linux, and preferable for longevity sake? Presently I'm looking at IBM thinkpads...

This is a little more than barebones, but it is a great Linux machine, and usually available at very low price (~$500 USD)... See if you can find an old Toshiba 5105 series, like the 5105-s607. They have a beautiful 1600x1200 screen with NVidia graphics (fast enough for most games with the proprietary driver), 1.7GHz P4M, 512MB RAM standard, 40GB HD standard, working Firewire port, 3 USB 1.1 ports, great sound system with subwoofer, and a secondary display/touchpad (Syntaptics cPad) which is supported. The only thing that doesn't work is the built-in proprietary SM/SD flash reader.

You can usually pick these up on EBay for under $500, and they are probably the best laptops Toshiba ever made; they went downhill after this (2001) series.

Edit: I forgot to mention it also has a working TV and VGA out, so you can run two-headed, or play movies on a TV while using the laptop display for other applications.