I have been using a T42 ThinkPad for several years ... Thanks for all the input. Just took a closer look at the T42 offer and decided to look for another one (you know, internet auctions are like flea markets).
Now I also registered at http://forum.thinkpads.com - quite a good ressource about the hardware. Will be probably back with 'how does NetBSD perform on a Thinkpad xxx'. Merry Christmas! herb langhans