EddieB

Great concept, and I really wished it worked for me (going to try another provider to see if they can do it properly), but execution was really poor with phone.com. I travel a lot with my job and need a phone service that can do so with me. The idea of phone.com was appealing so I attempted to set up an account and try it out. The setup process is very difficult to understand. I would recommend that you don't try to figure it out, just contact customer service and have them walk you through it. Some CSRs are really great (others no so much).
I was really excited about two things: Mobile App, and Softphone. I wasn't able to get the mobile app working properly (but this can be my particular situation, and can't ding them for it), and the softphone is difficult to get set up. It is also very heavy and designed for a call center (I think they just use a prepackaged softphone product, with little configuration). I had long system boot times after installing it, and it took a while to log in (skype is much faster and lighter - never thought I would say that!).
What really got me was that they locked my account because I wasn't in my home area. To me that was the whole point! The really bad part is not that they locked it, but they didn't notify me. It took me contacting them to figure it out, and the process to get it working again seemed long and complex. At one point it is just not worth it.
TL;DR: If you are looking for a mobile voip solution that is solid, keep going, nothing to see at phone.com.