fabFORCE.net: Here’s a really fantastic MySQL administration tool. Open source, even.
DBDesigner 4 provides powerful features to create a visual model of any database. Starting from a reverse engineering engine to automatically retrieve a model from existing databases, extensive modeling tools and editors to a syncronisation function which will apply model changes automatically to the underlying database — it is all part of DBDesigner 4.
The screenshots are phenomenal. — better than the default tools that come with SQL Server and its four- or five-figure price tag.