free database modelling software What is available in the realms of database modelling software that is free.  I am developing an SQLExpress database.

CA ERWin - community version
  although is free, I can't see an option to allow me to create a database, either using a direct connect or via creating an SQL script file.

Embarcardo ER/Studio - 14 day trial
  Can I reinstall this every 14 days?

What others are there, that will allow me to model my database and create a "create" script or "update" sql script?

Thanks in advance.
There are several choices:


SQL Power Architect (download without registration from Google Code). This is open source, but it seems there is no further development.
Oracle's Data Modeler (but it only supports Oracle, SQL Server and DB2. PostgreSQL for example is not supported)
A free version of TOAD Data Modeler - although that has some serious limitations on the size of the model
Open ModelSphere a general purpose modeler (including UML) but can also be used for ER modelling