I case you haven't heard of EarthConnect we're a pure XML web services
company based in Seattle. We currently provide financial information - yes
we're the guys who do stock quotes for real!

We have developed an industrial strength web services framework using .NET
with all that that implies - authentication, authorization, auditing,
interop, scalability, ..

To sign up for our FREE beta use this link: http://www.earthconnect.net
our SDK is documented here http://www.earthconnect.net/galapagos/sdk/.