Ciao anidel, I suppose it depends on how much you use your phone. Some possible snags: A. Latency. 3G connections give a lot of bandwidth, but they're not all super-responsive. Skype/In/Out is cheap, but I notice more latency that on a regular phone call (after all, it's an internet call plus a PSTN call). Combining those two (or even just the 3G part) could result in suboptimal performance. B. Battery life. My phone (on which nobody calls me) goes 10 days between charges; I charge my n800 at least once a day. That's 2 hours of being plugged into the wall, during which I don't have autonomy. Can you sacrifice the mobility? C. Size. The thing is cool, but it's a little too big for a phone; and you'd need to run a headset (Wired or BT) for practical calling. D. Complexity. Your proposed telephone system is: PSTN->Internet->Cell Network->BT Data Modem->N8x0->BT Headset As opposed to PSTN->Cell Network->Handset Each step represents a point of failure, and each connection an axis of failure. You are replacing a 5-failure-point system with one that has 11. In terms of likelihood of failure, in the "handset" system, you're likely to lose your cellphone connection (move out of coverage, interference, trying to make a call after a soccer match featuring your home town) or your handset functionality (breaks, battery dies, gets stolen, left at home); for the proposed system, you've tripled the likely failure points. So give it a shot, and let us know how it works!