When developing for CRM, we like to keep our business login contained within its own class to be shared and used by other parts of the system. Most all of our CRM implementations have other applications accessing CRM in one way or another so this approach works well. This was fairly straight forward wtih the 3.0 callout model, you just had to put them in the same directory with your custom callout (C:\Program Files\Microsoft CRM\Server\bin\assembly\ in most cases) . The way around this is to either...