I've signed and uploaded my RPMs. They're all now in http://turnipspatch.com/misc/rpm/, with a GPG key too. If anyone can test them out I'd be extremely grateful, be aware that if you're going to try to rebuild the SRPM then you'll need to install Per's rebuilt gtkmm packages (http://www.stanford.edu/~perbj/Fedora/inkscape-deps/) first otherwise it will crash on startup.
Another option for all you yum/apt repo usin' mofos out there is:
libgc from Dag RPMs http://dag.wieers.com/packages/libgc/
glibmm, gtkmm24, and libsigc++2 from NewRPMs http://newrpms.sunsite.dk/apt/redhat/en/i386/fc3/RPMS.newrpms/
After you've got these packages (and their devel files, of course), you shouldn't have many problems compiling Inkscape 0.40 (unless you're using a newer GCC 3.4 which craps out on an anonymous Radial object in nodepath.cpp [see my previous email for a fix to this]).
With the standard FreshRPMs, NewRPMs, Dag RPMs, and Dries RPMs in your repository list, it's as simple as:
yum install libgc libgc-devel glibmm glibmm-devel gtkmm24 gtkmm24-devel \ libsigc++2 libsigc++2-devel
Btw, see http://dag.wieers.com/home-made/apt/FAQ.php#D about repo compatibility. Especially if you're in the world of Fedora Core 3, you should ditch fedora.us and livna.org in favor of FreshRPMs/NewRPMs/Dag/Dries combo.
I've sent a self introduction to the Fedora.us development list, so hopefully I'll be able to get the packages in QA soon.
You're wasting your time. *smile*