In Exchange 2007, Outlook Web Access (OWA) offers a portal for users to manage their Exchange Active Sync (EAS) devices.

How to access that information?

1. Log on to OWA
2. Click "Options"
3. Click "Mobile Device"

Here is what the page looks like:

Note: If ActiveSync is not enabled for the Exchange user, "Mobile Device" tab won't be shown. You can run the PowerShell command to check the status. Here is the result from a test server for example: