I've just rebuilt and uploaded a new ppp RPM - this one should be built for generic i386 machines and includes the pppoatm.so plugin.
Thanks to Tony Hoyle for uploading a patched ppp 2.4.0 .deb and the tarball. You can find them (along with the existing RPMs) in the files section of this site.
I have now uploaded a tarball that contains all the files needed to make a ppp RPM. This should help out the various people who can't use my pre-made RPMs (ie non-RedHat users, non-glibc2.2 users, rpm3 users and seemingly almost anyone who tries them ;)
Thanks to Andrew De Quincy the pppoatm patches now apply to ppp-2.4.0 instead of the older 2.4.0beta2.