If you need to do some SQL Server 2005 or 2008 audit activities on DDL and DML operations this tool may help you.

Download: Effective Permissions Tool

In order to use the tool you need sysadmin privileges and xp_cmdshell enabled on the database server.
Before running it, create the following stored procedures on master db:

• Data Collect: this script will configure trace files with the event classes to audit.
• Data Reduce: this script reads the information stored in the trace files.

If you are interested on some more details you can see our slides (only spanish, sorry...)

Slides