Thanks very much for your response.
I prefer the simple solution, but unfortunately I am not able to use because we are in a secure environment and our client workstations are allowed no Internet access even via a proxy server. I also think is would be nice to have the WMS because I have plans to use it to provide a single source for other spatial layers .
This means I have to use the more complicated method, but I don't think it should be that much more complicated.
I would like to incorporate the WMSLayer at the client, which would then come into a local WMS Server. Somewhere in the local WMS Server the request would be intercepted and then sent on to the nearmap WMS Server. I'm thinking that the WMSLayer request would be intercepted in GetMapConfigurationCore and/or GetMapOverride.
Do you have any ideas on how the WMSLayer request might be passed-thru the local WMS to nearmap WMS?