I've seen lots of ways to backup a single repository in subversion. Is there any way to backup all the repositories in one go. I have lots of repositories for different projects and don't want to have to create a script every time.
If you have configured all repositories to use the fsfs backend, then you can use regular file-based backup tools (such as tar, dump, rsync, ...).
If you use bsddb repositories, I recommend to convert them to fsfs, with a svndump/restore cycle.