I've recently installed Exchange 2007 and have been trying to get ActiveSyn up and running to sync with my Palm Treo 750. I knew that Exchange 2007 comes with a self-signed cert but didn't know how to get at it or import it into Windows Mobile. Fortunatley the proceedure is very simple and is detailed here.

In case you are wondering the brief steps are as follows:

1. Open IIS and go to the Directory Security Tab of the Default Website.
2. View the Certificate and Click the "Export to File" button.
3. Accept the default options and save the cerificate somewhere you can remember.

To import into Windows Mobile:

1. Copy the .cer file to your Windows Mobile device.
2. Using the File Explorer on the device locate and open the .cer file.
3. Select yes.

Enjoy!