Instant Messaging(IM) on Windows Mobile(WM) seems like it would be simple to implement with four major IM providers offering solutions.   However, when it comes to WM, not all solutions are created equal. GoogleTalk and Yahoo! only offer web browser based IM.    AIM has an application client which looks and works very well.   However, the overall winner is the Windows Live Messenger (formally known as MSN Messenger) client.  A nice advantage of the Windows Live Messenger is that the application comes embedded into WM and a login is the only setup step required.  Live Messenger sets itself apart further by offering one other feature; let’s call it ‘Push-toTalk’ IM.   Any microphone equipped WM device can record a message with just a single click to record and another click to send.  The voice clips are transmitted nearly as fast as any IM message and can be replayed multiple times or saved.   I was very impressed with the sound quality through such a simple connection.  All IM conversations can be archived and viewed at a later date.

Alternatively there are several 3rd party IM programs such as Fring or Agile for example, which facilitate the use of multiple simultaneous  IM carriers.  www.fring.com    www.agilemobile.com
While researching the Google solution I did find an application that showed much potential - Google Latitude.  With this free and easy to use application you can see the current location of all your contacts.  In the mobile arena or DSD, it is a great way to be able to see the location of all mobile assets. 
And for headquarters there is an iGoogle plug-in that integrates easily and allows for asset tracking.  Tracking is accomplished via assisted GPS and is therefore accurate within 1600 meters.  A GPS enabled device is not required.