Oh, duh.
We're talking buffers, aren't we?! That little buffer schematic that lovecraft posted looks a lot like the schematic I linked to, except that Tillman circuit is set up for service as a preamp more than a buffer. I like that Tillman circuit, because while it is a preamp, it's not amplifying the signal that much. It's maybe 3dB or so. It's really made to compensate for cable losses, etc., so in my mind it's something between a buffer and a preamp. Isn't a buffer supposed to be a guard against impedance mismatches and tone sucking due to cables and stuff? To me, they are close to being the same thing. Anyhow, the one guitar that I put it in really sounds better to me than before. It has also has the side effect of making a hot output humbucker even hotter. That's why in my current project, I am going to have the option to switch the preamp on/off. YMMV.