Playing around with TFSDeployer on a SharePoint farm, could not register the service right on port :8881 and when I tried to run TfsDeployer in debug mode I would get this error message:

C:\Program Files\TfsDeployer>TfsDeployer.exe -d
System.ServiceModel.AddressAlreadyInUseException: HTTP could not register URL http://+:8811/BuildStatusChangeEvent/. Another application has already registered this URL with HTTP.SYS. —> System.Net.HttpListenerException: Failed to listen on prefix ‘http://+:8811/BuildStatusChangeEvent/’ because it conflicts with an existing registration on the machine.

ran the following command:

netsh http show servicestate

Found that a SharePoint site was bound to port :8881

As it was a site set up for testing purposes, I just went in and changed the bindings in IIS to a new port and updated the default zone to the new port number.