Voip
I agree with this article. At my current position, we have huge issues with dropped calls, unable to hear the other party while one the phone, can't dial out are just some in growing list of issues.
However, the functionality of the service are fantastic. Working in the IT department, I am responsible for desk moves and part of that is moving phones with it. Because most companies are currently wired for the internet anyway, rearranging the office is so much better because I don't have to worry about whether or not there is a phone jack on the other side of the room or under a desk, the data ports are always there.
I honestly believe this will be the way of the future, but for now I think the technology is too new for it to be considered significantly better that a a regular phone connection.