I've been wanting to use Rails with a master/slave MySQL setup for years. But the problem we've had is that ActiveRecord can't be told to read from one server, but write to another.

We considered writing a plugin for this, but then found the ActsAsReadonlyable plugin. The good news is, this might not be necessary, as I recently discovered this MySQL Proxy tool that can do read/write splitting!

This looks really promising to me, anyone tried it?