Photo: Trento, Italy picture taken by Denise Morrison. Trento is a charming place to visit and is popular with California travelers, offering great picture taking–but those pictures comes at a price if you plan to post to Facebook on the spot. When the urge to post comes, hold on. That one data transfer may cost you $20-40. Is it worth it? Here are some ways to save money when traveling outside the U.S.

• Purchase a prepaid Sim Card – Mobile phone providers charge exorbitant fees (data and roaming) to use smart phones/mobile phones in foreign countries. A prepaid Sim card offers rates to make an international call as little as 49 cents per minute and ability to receive free calls in over 75 countries (using a global UK number). And prepaid data is available in 135 countries for as little as 39 cents per MB.
• Know fees before you go – The major cell phone carriers charge $1.29 to $2.59 per minute for international roaming, and more for data– $15 to$20 per MB for data. That's $20-$40 to upload a photo of the Eiffel Tower to your Facebook page. Telestial charges as little as 39 cents per MB for data. Upload photos, check emails or download music for a fraction of the cost of the major carriers.
• Get free calls on your mobile phone – With a Telestial Sim card (telestial.com) you are assigned a US number and a UK number. Give the UK number to family and friends, and incoming calls cost you nothing.
• Invest in an unlocked GSM Phone – To use a prepaid SIM card (like Telestial), you need an unlocked GSM phone. There are two mobile phone standards in the United States: Global System for Mobile Communications (GSM) or Code Division Multiple Access (CDMA). Sprint and Verizon Wireless use CDMA, which is not meant for global travel. AT&T and T-Mobile use GSM, considered the global standard for cellular networks. Most mobile phones sold by GSM carriers in the U.S., however, are locked. The iPhone, for example, is locked to AT&T. If you're with a GSM carrier, and want to purchase a prepaid SIM card, you have two options: unlock your phone yourself (unlockingcodesforphones.com) or purchase an “unlocked” international phone.
• Beware Skype overseas – When connected to Skype, make sure that you are using free WiFi (from the hotel or a coffee shop), and NEVER use AT&T/T-Mobile's roamed data services. Also, some countries with state-run telecommunication and Internet-providing companies block VoIP services like Skype.

• If you use an i-Phone, turn off apps, data roaming and fetch data
• Every time these update, you're burning precious data … which is precious cash.
• Don't upload vacation pictures while roaming on smart phones. This can be extremely expensive, as many photos are more than 2 to 3 MBs each. Instead, hold the photos until you have access to the internet (at your hotel) or wait until you return home to share your experiences with the family.
• Purchase an international charger adapter to charge your phone.