You can contact the organization service using any language as long as they can handle REST based web services, I guess.
As a side note, if you intend to work with Dynamics CRM, you'll probably want to skip PHP and transfer more into C# and JS. Sooner or later (i.e. sooner), you'll be building plugins (that's C#) and customizations of the client-side (that's JS).
I may get my head bitten of for this but I don't think that PHP can be used to work towards CRM very effectively.
Having said that, I can think of a few scenarios where PHP might be a better choice but being a true MS slave (our offices in Stockholm are in fact right above Microsoft's. We're on the top floor of MS building here.