I've mentioned distributed version control systems a few times. It was interesting note the advice that Savannah is giving about recovering from a recent disk crash. Both Git andMercurial based projects can restore from local repositories as they contain all the revision history within them. The centralised version control systems are relying explicit backups being made. History has proved that getting backups done right is harder than it looks. If your running an open source project there is a lot to be said for having ever developer mirror you code for you. To slightly misquote Linus*: "Only wimps use backup: _real_ men just upload their important stuff and let the rest of the world mirror it".
* The original quote mentions tape and ftp which dates it a bit.