I'm always in favour of technology which solves the replication issues in mysql. It's been one of the most painful parts of managing databases for myself.

I would like to throw in the tungsten replicator into this discussion http://code.google.com/p/tungsten-replicator/. I have been researching it for the past few weeks as a replacement to mysql's built in replication hoping to solve a lot of the current pitfalls especially in 5.0.x. There is a very thorough guide here http://tungsten.sourceforge.net/docs/Tungsten-Replicator-Gui...