How can I get alerted when auto-growth occurs on a SQL Server database?

Our SharePoint databases are set to the (nonsensical) 1MB default autogrow out-of-the-box, and I need to "convince" our application owner that this is wrong. Is there a means to monitor the autogrow activity of SQL Server?

I would like to be able to report how frequently this activity is occuring with the 1MB setting.

As further ammunition for you, checkout this blog post I did which discusses data file auto-growth: Importance of data file size management.

Log file autogrowths are reported in the SQL logs or the Application event log. You can also use things like SQL Trace or SQL Profiler to monitor SQL events. Here's a MSDN article that discusses monitoring SQL events.

EDIT: In the Application event log look for Event ID 5144 for autogrowth cancel events and 5145 for successful/completed autogrowth events.

EDIT2: To look for db log file auogrowth events in your SQL log you can use this:

EXEC xp_readerrorlog 0,1,'autogrow'

Increment the 0 in order to have xp_readerrorlog use archived error log files. 0 to (n-1) where n is the number of error log files you have.

You can also set up event notifications for an autogrow event. Something like this:

CREATE EVENT NOTIFICATION data_file_autogrow_notifier
ON DATABASE
FOR DATA_FILE_AUTO_GROW
TO SERVICE 'NotifyAutogrow', 'current database' ;

or for the log file:

CREATE EVENT NOTIFICATION log_file_autogrow_notifier
ON DATABASE
FOR LOG_FILE_AUTO_GROW
TO SERVICE 'NotifyAutogrow', 'current database' ;

Where NotifyAutogrow is the name of a Service Broker instance. More info here. You would need to set this service up for your environment.