I use Skype for all my incoming and outgoing business calls. I have ever since 2006.
While I love Skype, what I really love is my Google Voice number. In fact, when you call my office number, you are calling my Google Voice number, which is then routed to my Skype-In number. Why don’t I just dump Skype and exclusively use Google Voice? Well, because there is no desktop app for Google Voice, so no easy way to dial-out using it.
TechCrunch has gotten their hands on a prototype Google Desktop app–still fresh in the Gizmo5 wrapper (the company is acquired in 2009). Here’s a video demo:
A lot more basic than Skype, but I only use the basic features of Skype anyway. I hope Google brings this to the public soon!