Best phone provider for international travel?

I am an American and would be traveling to South America, Asia and potentially Africa. Email, SMS, phone service all required.

I'm going to Puerto Vallarta from Oregon next weekend and I'm wondering if my cell phone will still work.....

I am looking for a call forwarding service. I would like to have a single phone number that would not change. I would then like to forward any calls to this number to multiple phones simultaneously. No call screening needed, just have whichever phone...

I have an old cell phone. I have a old digital camera. I have a simple mp3 player. I want GPS. I currently pay $60/month for unlimited calling (but no data) on my Tmobile plan. Can I get all or most of these things on one cell phone without spending...

I am in the UK. I live in Plymouth. My one year Vodafone contract is finally up and I hate them with a passion. I'd like to switch, but as a still relatively new ex-pat I don't know who to switch to. Can you recommend a provider to me based on my requirements...

I switched my individual cable, phone and internet services to one provider back in August 2007. I have had an ongoing problem of outtages with the phone/internet service portion from day one. It will simply drop and after some period (minutes to hours...

What mobile phone service provider should I use? I work in Acton, Massachusetts, USA, and live in the Boston area. My needs are fairly average: I use my phone casually, typically less than 1000 minutes a month. I don't need wireless web or other gadgets...