Our latest technical article has been published at :

http://msdn.microsoft.com/library/en-us/dnppc2k3/html/ppc_services.asp

This article deals with how to write services for Pocket PC 2003 devices.  This is useful for applications which need to run in the background and don't have any UI.  Why is this a good idea?  Windows CE has a limit of 32 processes running on the device at time.  If you write your app as a service it runs as a thread under the services.exe process meaning that you aren't occupying a valuable process slot.  And you want to be a good Pocket PC app citizen don't you?