Here's an elegant and likely economic solution to a problem that is often raised on Crackberry. It's well worthwhile to see if this will work for you. The services of
Call in Europe were recently recommended in a well known PC Magazine.
Travelers presently have few choices in maintaining their cell phone AND Blackberry data service while abroad. They can use their own GSM-compatible phone (if they had one), and their U.S.-based plan, and pay exorbitant international roaming fees and surcharges. They can rent a GSM phone and pay the extremely high rental rates and expensive per-minute calling charges. Or, they can buy a costly prepaid phone card and deal with complex instructions, restrictions and time limitations.
A firm called "Call in Europe" provides a cost effective solution, travelers maintain an option to maintain their US phone number, whilst simultaneously be issued a European number one for as long as required. There's plenty of information on the site, as well as direct cost comparisons using their service vs. roaming with T-Mobile USA, Verizon etc.
Solution for Blackberry data Low-cost Europe cell phones and European SIM cards
Quote from the site:
"If you own a BlackBerry® our services are compatible. Use our SIM card with your unlocked device and keep receiving your emails while saving a bundle on all of your data and calling charges!
Until now when you traveled abroad you had to activate an international data plan with your current carrier. Some providers even locked you up in a yearly subscription... but you still had to pay high roaming calling charges.
For Blackberry Internet Service (BIS) or Blackberry Enterprise Server (BES) users, we propose a flexible option that allows you to activate this service for the duration of your trip. Then you will pay simply for your usage.
How does it work?
Contact us to activate this option on your line. Then replace your current carrier's SIM card with your Call in Europe SIM card and continue sending and receiving your emails. This is that simple and no settings have to be changed. Or, if you already have an existing line with us, simply contact us before your departure to activate this option.
The option is only $0.50 per day. Tell us if you are a BlackBerry® Internet Service user or if you are a BlackBerry® Enterprise Server user. Then you just pay your usage as follow:
Within France : $0.005 per kb for web browsing (billing increment 10 kb)
Outside France : $0.015 per kb for emailing and web browsing (billing increment 10 kb)
Add and remove this option to your line without limit to suit your travel needs. Allow up to 72 hours to activate or deactivate this option"
Keep talking in Europe Low-cost Europe cell phones and European SIM cards
you don't pay outrageous roaming charges anymore
you can keep your US number or have a European one.
you just have to buy a SIM card for ONLY $29 and use it
An European SIM card
No monthly fees
No term commitment
Not a prepaid service
No connection fee
Keep my US Number
Keep talking in France Low-cost France cell phones and French SIM cards
With KEEP TALKING IN FRANCE, Call in Europe offers you the best cell phone solution to stay connected during your trips to France and elsewhere in Europe. You can keep receiving your calls on your US number with our call forwarding solution. You just have to buy a SIM card for $29 and use it.
You benefit from the lowest rates and you don't pay outrageous roaming charges anymore
A European SIM card
No monthly fees
No term commitment
Not a prepaid service
No connection fee
Keep my US Number
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Low-cost Europe cell phones and European SIM cards 
Travelers to Europe, Low cost phone and Blackberry solutions 
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