>I'd be interested to hear other options though...

Edward, we develop a commercial Windows tool named "Database Workbench" that
supports MySQL.

It does not yet do diagramming, but it's being worked at for v3, as well as
many
other features.

Have a look at www.upscene.com

Martijn Tonies
Database Workbench - tool for InterBase, Firebird, MySQL, NexusDB, Oracle &
MS SQL Server
Upscene Productions
http://www.upscene.com
My thoughts:
http://blog.upscene.com/martijn/
Database development questions? Check the forum!
http://www.databasedevelopmentforum.com