I tried Bobsled Calling on Friday.
I didn’t get to keep my number. My mother thought I was a spammer from Illinois. Good times.
My mother also didn’t recognize my voice and I cut out here and there. The delay was long enough that I would stop talking and wait for her response to come in. However, there’s no WiFi where I called so I was using Sprint’s 3G.
A five minute conversation bumped my data up for the day to 8.59MB (full disclosure: I also checked my email and used Google Maps). For those VoIP enthusiasts with a small data plan, reconsider. To replace cell with data, you need a fair amount available first. I will have to be more skeptical of free VoIP apps in the future. Depressing.