Wow, the responses I've gotten on this thread are WAY more extensive than I thought they would be... thanks everyone for the links! Yes, this kind of thing is exactly what I'm looking for.... how do you find this stuff? Googling "keyboard mod" doesn't seem to find much.
lowpoly, you are my personal hero. Transplanting a trackpoint is something I've dreamed of doing for a long time, but it seemed too ambitious for a first attempt at modding, so I thought I'd start with the numpad amputation and go from there. But the fact that someone has already done this successfully is very encouraging. I actually have a spacesaver II which I bought specifically for the purpose of harvesting its trackpoint, but I haven't yet found the perfect keyboard to use as a host. When I do, I imagine I'll have some questions to bounce off you about the details of how you did it.
Incidentally, I just bought an Omnikey Evolution (off the marketplace on this forum)... I don't have it in my hands yet, but the layout seems really nice, and the trackpad, although probably not usable as a primary pointing device, should be useful at least for an emulated scrollwheel. Hopefully I'll end up liking the feel of it enough to use it as my starting point to begin modding. Does anyone have any pics of the internals of this board, or any threads on modding it?