Can you setup your cellphone for dual sim card function to receive call from
both sims without having to switch the sim ?

I am looking for a cell phone module or modem that can be interfaced
to a microcontroller. I wish to poll a circuit remotely using SMS
messages and get short messages in response. The desired features are,
1. compact size,

I have had more problems with Alltel Wireless than I can tolerate.
I am investigating other services.
How satisfactory is AT&T wireless?  Are they robbers with the rates?
Alltel has totally unrestricted use.  A flat charge by the month.  $59.00.

Cruising through our defunct Circuit City yesterday, I stumbled upon two
Sony TMR-BT10 Bluetooth Portable Stereo Transmitters brand new in the
currently 20% off category.  They were already discounted to $25 and
change but CC's liquidators took off another 20% and the final price ...