Okay, I talked with Bob and I now understand what's going on. We're not doing a static binary (where ldd returns nothing), we're linking various libraries statically. The goal is to make certain weird ones static, and leave the more common stuff.
Basic steps: compile libraries statically, link inkscape against those.
I wrote up a quick Wiki how-to: http://www.inkscape.org/cgi-bin/wiki.pl?CompilingStatic
and then modified the inkscape.spec file to allow static library linking. Unfortunately, I've got Debian, so my built RPMs are a little weird. :)
I didn't want to "publish" my goofy RPM on Sourceforge, but Bulia wanted to see it, so here it is: http://outflux.net/inkscape-0.40cvs-CVS.i386.rpm
(don't ask why it's named all weird... must be RPM magic.)
Using "alien" anyone can easily convert this to a tarball, too.