Why Has Your Business NOT Integrated VoIP

I just posted about a white paper from Quintum in my last post, and that triggered a thought...a question. If your business hasn't already integrated VoIP in some form or fashion, why not? What's holding you back? I find that every forward-thinking business I work with, both large and small, has recognized the value of voice and data integration and already made some move to shift heavily to some integration of VoIP technologies into their corporate voice services. It's not a cutting edge, dir