Server Upgrade and DB Move(s)

I am in the process of upgrading my UNIX hardware and moving web sites from two different servers on to one server. I am curious as to opinions about moving/replicating the databases and peoples experiences. For the two that i have already done, i have taken a rather manual approach which was easy, but the rest are more dynamically generated and dependent on MySQL and I was looking for a tool that could replicate the structure and data onto a new server. Anybody find an easy way to do this. I could write something in PHP, but if i could, it's probably already written.... Thanks in advance. Jeff