For Mac users out there, who wish to have a native ERD tool with SQL script generator tool, I would recomend looking at XERD. It is available to download as shareware from http://www.versiontracker.com/dyn/moreinfo/macosx/22456
ProductDescription:
XERD can create Entity Relationship Diagrams with ease and automatically generate the SQL table creation scripts to make your whole database.
'Crows-foot' entity relationship diagramming
SQL script generation and export
Support for PostgreSQL, MySQL, Oracle and SQL 92
Multi-level undo/redo
Customizable working environment
Show relations feature
Easy to use MacOS X interface
Contextual menu support
Concise documentation
Product Requirements:
Mac OS X 10.2 (Jaguar) or higher
Thanks go to Thunder for bringing this to my attention.
HTH