I have a pair of svn repositories which are significantly larger than others. They\'re not too big for svn, but they\'re taking a lot of disk space I\'d rather be using for some
If the used disk space is more important for you than the version history, then you could make a clean checkout and reimport your projects into a new repository. The old repositories could then be stored in a compressed archive.
If you don't want to lose the complete history, then this article might be interesting for you: Delete parts of subversion history