This sounds like what you're looking for:
http://www.sparkfun.com/commerce/product_info.php?products_id=757

For service, you just activate a cell account with GSM service and plug your 
SIM card into the module.  You don't make any special arrangements with the 
cell company, you put it on whatever plan you want.  I'd recommend a 
pre-paid plan; it's usually something like $25 every 3 months for up to 100 
minutes.

I have never used this module though.

----- Original Message ----- 
From: "Harold Hallikainen" <harold@hallikainen.org>
To: "Pic List" <piclist@mit.edu>
Sent: Monday, October 16, 2006 2:59 PM
Subject: [ee] Embedded cellphone module?


>I have an application where an embedded cellphone module would be useful.
> I'd like something that does low speed serial data (14.4kbps or so) over a
> national (US) cellular network. Data would be exchanged infrequently (once
> a week to once a month). Does anyone know of such a module and what sort
> of arrangements can be made with cellular companies to do such data
> exchanges at off peak times, ideally only paying for data exchanged
> instead of a "per unit" cost?
>
> THANKS!
>
> Harold
>
>
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