Just saw that there is now a linux standalone tarball, I've a SL5 (RHEL5) based machine which I can churn out git-annex binaries if there is interest.
I'll be curious to see if the standalone tarball works on such a system.. it might need a newer libc
than RHEL5 has.
Conversely, that'd make it a good system to build the tarball on, so it's built to work with a nice old libc.
I have a machine where I could put chroots to do both 64 bit and 32 bit builds, but I don't know if I'll automate it there. Too lazy..