Based on Torsten Duwe's great work (currently in the Buildservice in home:duwe:crosstools), which is building but not working 100% correctly, I fixed the powerpc version up (I have no other architecture to test on) and put them into the openSUSE Buildservice in home:seife:cross for now.
Get them from here: http://download.opensuse.org/repositories/home://seife://cross/SLE_11
(don't get put off by that SLE_11, the cross compilers should be pretty system agnostic. For testing I ran them on a SLES10 which is probably older than anything you want to use, and they worked just fine)
Edit: I just found out that this only works because I have a patched rpm on my SLES10 which understands lzma compression. I have added SLES10SP2 to the repository so that pre-LZMA-rpm distributions still can use it.
So if you need a powerpc crosscompiler, just add that repository, install packages "cross-powerpc-embed-linux-gnueabi-binutils", "cross-powerpc-embed-linux-gnueabi-gcc", "cross-powerpc-embed-linux-gnueabi-glibc" and "cross-powerpc-embed-linux-gnueabi-kernel-headers" and you are ready to go.
Make sure that /opt/cross/bin is in your $PATH and configure your project for target "powerpc-embed-linux-gnueabi".
Still TODO: get them into a proper semi-official project.
Oh - and of course I already changed my favourite embedded projects so that they are now able to build with an "external" toolchain ;)