This summer, I discovered Google Voice, which is turning out to be more beneficial than I'd first thought. Here in Ukraine, I have figured out how to use Google Voice (sometimes in combination with my Skype account).
Originally, I used Google Voice in the US so that one of my friends could call a number (local for them) that would forward the calls to my cell phone. I had set up two different numbers (with two different email accounts), and one of them was with a Maryland area code for my "experiment."
In the States, this is how Google Voice works, and there is a centralized voicemail for all your phones.
Friend --> GV number as intermediate number --> Your phone (cell, home, work, or all of them) rings
While in the US, I have a Verizon phone with a monthly contract. This contract is put on hold while I am in Ukraine, so I don't pay for a phone I'm not using (so a two-year contract turns into three years). I have used my home phone number as a contact while in Ukraine, but my mom is cancelling that number since we all have cell phones.
If I want to contact anyone in the US from Ukraine, I use Skype if they are a Skype user or if I am calling a 1-800 number. Sometimes I use Skype to call phones (for the whole conversation or to have them call me on Skype), but this costs about 2 cents a minute, so I usually use it for calling internationally during the summer.
Here is where Google Voice comes into play! If there is no answer on any of the phones, Google Voice records and transcribes your voice messages and notifies you by email (which can be VERY entertaining sometimes). My family (or others I am trying to contact) can leave me voicemails,
which worked out VERY well in the spring of 2011 while I scheduled
services at churches. You can also send a free SMS to any US phone. Now, I can use my Google Voice number as my "home" number so that those in America can contact me! It's long-distance for my family, but at least it's not an international phone call.
Unfortunately, Google Voice does not have local numbers for all areas, nor can it forward calls to international phones (that would be AMAZING, though). For now, Google Voice is still rather practical and now I do not have to use my "Hotspot Shield" while in Ukraine.
When you're a missionary, you've got to be thrifty and inventive with what you have.
(updated September 2011)