At the request of a few developers, I set up a mercurial (http://www.selenic.com/mercurial/) repository that mirrors our SVN one.
It is updated automatically from SVN every 30 minutes. Note *only GCC developers have access right now*. I will make it available by http anonymously soon. The url is ssh://gcc.gnu.org//hg/gcc/trunk (double slash is intentional) While you *can*, please do not push to this repository. I have not yet set up the outgoing commits to svn, but I will soon. The repo is ~230 meg. The repo does not currently contain the full history of GCC, but this is my fault :) I started the pulling on my mac and got screwed halfway through when I hit case insensitive name conflicts. I have restarted on a linux box :) Note that it looks like a repo containing the entire gcc history is going to end up being ~500-600 meg. I'll send another note when that repo is done.