Last week (at ApacheCon 2009 EU) I gave a session talk about "Subversion on-the-fly Replication" and how we (ASF) deployed such an setup last year with in the Apache Software Foundation. So check out the slides if you are interested in how it works, why you should do it, what are the known problems and the solutions etc..
Thanks to all the people who attended the session I (we) are still open for good suggestions and feedback ;-)
There is no need for being sad if you missed the session talk, it was recorded as part of the "HTTP Server Administration" track. You can register for it HERE
Ps: Thanks to Tony Stevenson to act as my session chair and to Paul Querna to help out on answering questions ;)