> I think you'd be far better off buying a popular cellular phone and
> interfacing it. You have the BIG cost advantage of "It already works".
> You won't have to deal with the cost and difficulty of
> designing/debugging a finicky RF section and meeting ALL the
> regulatory specs. Buying a mass market product ensures that
> you will have a much lower unit cost AND and an ongoing supply of
> used phones to draw upon should your supplier discontinue the model.
> Try replacing a chip set 3 years from now. 486/66 anyone?

You might be better off buying a handset, granted.  Just want to point out
that both handsets and modules use AT (as in modem) style commands, which
are standard AFAIK.  Also the RF section is included in the module (i.e. you
are not buying a chipset, but a module that has a chipset and some other
circuitry incorporated).  Many even have a co-ax plug for the antenna.  And
a unit that is  soldered into your board is much neater and more
professional than a cell phone.

Roland