I also had a look at the BT SDK in the last week.

Wow! This is a shining example of a) some great functionality to exploit and b) a really well produced SDK, samples and service package.

What does it do? Take a look at the site, but essentially it allows you to programmatically invoke SMS, Voice Calls, Conference Calls etc. from web pages and the like (some of the samples demonstrate things like a call queuing system using the SDK and MSMQ).

I initially baulked at the install as I saw mention of X500 certificate installation and application registration and the like, but actually the tools that shipped with the SDK made this extremely simple, and I was up and running in 5 mins.

Well done BT for producing something so useful. Try it out.