If anyone is interested, there's an article in the Feb. 2005 issue of C/C++ Users Journal by Neil Roodyn entitled "Mapping, Web Services, & C++".
It talks about using the MapPoint Web Service using C++ in an embedded application (an MS Smartphone). Rather than using a toolkit, he handles the SOAP/etc directly.

My understanding is that aricles and code can be downloaded from the CMP website at http://www.cuj.com
You will need to be a subscribe of C/C++ Users Journal or a partner magazine (DDJ, Byte.com, etc)