SQL Profiler is a wonderful tool being wide used for system monitoring, performance monitoring, debugging, etc. ( you can count more than I do ;), I better shut up.) It provides tons of events triggered by SQL Server from different areas for various purposes. You are allowed to create customized event for your own by calling sp_trace_generateevent. There is already an example in BOL that you can trace get notified whenever a record is being inserted into a table. It quite useful when you try to centralize the error messages or some other stuff. Well, if your database is serving a busy website where the user management is application type user permission management, you are asked to keep track of every procedure calls with application user tied with, customized event will come to play. This was the one I have done before. Please feel free to tell me your story with customized events by replying my post.