There are a lot of OS that supported by Smartphone.
Palm also have their own OS. Some other phone use Symbian OS, etc, etc.
If you are familiar with Palm OS, It might be a lot easier for you to write Software for your Palm Smartphone.
Presently, all the smartphone equipped with WiFi, Bluetooth, and GSM capable of sending/receiving Message.
In my opinion, If you want to interface FEZ with the smartphone, my choice of platform would be Window Mobile OS.
Because Window have bigger brother of .NET Micro Framework namely .NET Compact Framework as the plateform
for developing Window Smartphone App.
Since you’re already familiar with .NETMF it should take you a minimum amount of time to get familiar
with .NET Compact Framework.
[quote]Utilization ideas for this concept so far are field updating of firmware, collection of stored data, wireless control via sms/modem.
To do field updating the software is beyond my knowledge.
For collecting/storing data, again Window smartphone provide you a way to do that with SQL Server Mobile,
It won’t be hard to do wirless control via Sms/Modem. There are a lot of sample codes available on the internet
or MSDN website.
This is on the smartphone side.
Now, on the FEZ side, if you only can equip your FEZ with GSM modem, WiFi, Bluetooth (Serial Interface)
You should be able to use FEZ to talk to smartphone.
Hope this help