In the US, T-Mobile has a few phones that can route calls over wifi. This does not use minutes, OR special hardware other than the phone. Sprint has a (CDMA) femotcell which you can pay a monthly fee for (like $10 or so a line) and call on it for free. I think you can not pay the fee and have calls and data bill like normal too. Verizon has a (CDMA) femtocell, it also is just bills minutes and data as usual. AT&T doesn't have it together, last I heard they had STILL not launched a femtocell, but it's going to be UMTS-only when it is launched (no GSM support.)
[QUOTE]In spite of the tiny slices of spectrum available, self forming mesh networks are the future.[/QUOTE]
They've been saying that for a LOOOONG time. With the limited range available, I think something like an 802.11 mesh can be useful but it's a limited replacement for other technologies (despite the objections I list I do plan to look into 802.11s -- the recently ratified mesh standard -- sooner rather than later) -- 1) Anything resembling a "backbone" from one end of the mesh to the other will have very heavy traffic, if this traffic goes via mesh there'll be the low battery life (of devices constantly forwarding packets) and overloading that'd imply. Fine for SMS perhaps but voice and data, perhaps not. 2) The mesh will extend a certain distance, then the next users will be too far away to be able to join and extend the mesh. 3) The mesh does have to connect to something eventually, telephone network or internet, if it's going to be more than just a island of coverage that can only talk to each other. So someone will have to have like an asterix box or ISP account that doesn't object to tons of traffic constantly running over it.