There are two different points here. First, it should be easier to switch phones between providers using the same technology. I believe the issue here is that the manufacturers "lock" the phones. But for a small fee (do a google) you can find plenty of folks who will unlock your phone. You can also buy an unlocked phone, but you won't get the subsidy.

Going back and forth between TDMA and CDMA is more complictated as these involve different compression technologies, not just different frequencies.

How about standardized everything electronic. It's just ridiculous. I work at a large printer-company, and testing 20 printers, have to come up with 20 power supplies, ink cartridges, etc. I don't understand why we can't have stardardized everything when it comes to electronics and have much fewer producers, perhaps.

Partly innovation, in that if somone defines thigs as a defacto standard, one could sometimes not really not bend them much to achieve new ideas.

The other reason not to standardise, is the Razor model, you sell the hardware cheap, even possibly at aloss, and have people buy only your consumables.

As for the Cell phone, it is a doable concept, have a format specific transciever unit connect inside a box that has a display, keypa, earpiece, microphone, and battery. Of course at the expense of miniaturisation and advancing standards.