download here: http://www.microsoft.com/downloads/details.aspx?FamilyID=4bbe7065-a04e-43ca-8220-859212411e10&displaylang=en
It wouldn't work when I installed it. I had my default web site stopped when I did the install. I started the web site, and installed OWAAdmin again, but still didn't solve the problem. Had to right-click and uninstall the OWAAdmin.MSI file. Then I installed again, and all was well.
Guess what? You don't need to do manual segmentation anymore, you can use this tool.
I keep getting prompted for credentials when I access it, I assume it needs admin rights on the exchange server.
I also had to re-create the client side scripts for .NET:
C:\WINNT\Microsoft.NET\Framework\v1.1.4322> aspnet_regiis -c
Start copying the ASP.NET client side script files for this version (1.1.4322.0).
Finished copying the ASP.NET client side script files for this version (1.1.4322.0).