Hello,

We're trying to look at a few PDAs which come with or have the option
to enable them with a GSM/GPRS phone as a form of remote data link to
connect their mail and calendar to MS Exchange.

Is that doable?

/Lizardnation

Hi once more! Thanks again for another question.

Yes it is possible and doable for a Pocket PC to be attached to a VPN
using GSM or GPRS. Here are the following examples:

1. movianVPN

"movianVPN is a fully configurable, broadly interoperable, Virtual
Private Network (VPN) software client that connects to VPN gateways
over a wired or wireless connection. With movianVPN, you can exchange
e-mail, use enterprise applications, and access work force information
or enterprise resource planning data while minimizing the risk of
interception or unauthorized use while it travels over the Internet."

"For Windows CE versions, movianVPN is compatible with Pocket PC 3.0,
Pocket PC 2002 and Handheld PC 2000. movianVPN has been designed to
support a wide range of mobile devices."

movianVPN has been tested to run in different IP based services which
includes GPRS and GSM.

movianVPN
http://www.certicom.com/products/movian/movianvpn_gen_FAQ.html

2. Columbitech

"Previously, Columbitech has shown roaming between CDPD, GSM, GPRS,
WLAN, and Bluetooth technologies on a PC notebook, and has now
successfully migrated their technology to a Microsoft (Nasdaq “MSFT”)
Windows® Powered Pocket PC, with a Palm OS® version to follow.
Columbitech Wireless VPN is the first technology to provide Pocket PC
devices with the necessary means to achieve true wireless network
interoperability combined with end-to-end security, which is an
increasingly important prerequisite for the widespread acceptance of
wireless data technologies."

"Columbitech First To Show Secure Wireless Network Roaming For PDA
Devices"
http://www.robertel.com/91page05.htm

After those examples, here are the following Pocket PC products that
you might want to look into which has the capabilities you require.

T-Mobile Pocket PC 2002 
http://www.mobileuniverse.com/products/phones/pocketpc/specs.shtml

Ipaq (Accessories)
http://www.expansys.us/product.asp?code=MOBKITWIRE1

Casio
http://www.pocketpcmag.com/Mar02/casio.asp
 
Search terms used:      
"Pocket PC" VPN GSM 
          
I hope these links would help you in your research again. Before 
rating this answer, please ask for a clarification if you have a 
question or if you would need further information. 
          
Thanks for visiting us once more.           
          
Regards,           
Easterangel-ga           
Google Answers Researcher

Very well done! :-)

/Lizardnation

Thanks for all the nice ratings and for the tip!