I'm still a Skype fan, mostly because most of my associates have Skype accounts, but I started out in the VoIP game with a standard SIP account at Sipgate.

The service rocked, and I used it a lot, but the software for the Mac was less than ideal, and incoming calls didn't always work. Having a genuine SIP phone might have solved the problem.

Based on this review it is very tempting to get one, but I'm still holding out for the first standalone Skype phone, preferably wireless.