Is this now dead?
He had announced a while back that that site was going away at the end of 2005, and SourceForge was the new "official" site. Here's a reference I found:
A 4.1.* release (or even 4.2.* since it seems to be nearing stability) would be nice..
I have patches for gcc-3.4.6 and gcc-4.0.4 at http://williambader.com/bounds/example.html
gcc-4.1 changed the C parser from an autoconfigured bison script to hand-written C code, so it would take quite a bit of work to update the bounds checking patches. If anyone is willing to work on the parser, I have patches against gcc-4.1.2 for all of the other files.