allalerts.codeplex.com
Get all alerts in a SharePoint Farm - HomeThis Powershell script can generate a CSV file to populate all alerts of all users in a Farm. This is particularly usefrul when migrating from SP 2007 to SP2010, where Alerts are not migrated. You can then use this CSV file to import all alerts in to the target SP 2010 system
http://allalerts.codeplex.com/