We have gotten a few questions about getting some sort of workaround for GAL lookups using Entourage with Microsoft Online Services.  While a couple of Mac users within our team have written a GAL lookup add on for Entourage, we cannot officially release it as a Microsoft product due to various reasons.

However, there are a couple of Apple Scripts on the internet similar to our internal solution that will enable GAL lookups for Entourage connected to Microsoft Online Services

http://www.entourage.mvps.org/exchange/exchangelookups.html

http://www.xutils.com/owagalsearch/

Note: The above information is provided as-is and is NOT supported by the Microsoft Online Services Support Team.