Interested in video ip phones for developers - Win CE/embedded

Hi,

I'm interested to try and play with open API video IP phones, to test some applications ideas.

Ideal OS would be WIN CE or embedded, that I can program to and operate various phone functions. Also it would be cool of the phone can use standard switching/pbx protocols - and not proprietary pbx - like Cisco phone do.

If anyone knows about relevant models, I should be happy to hear :)

Up to now I saw some links at MS

Thanks!