(DISCLAIMER: At least as far as I know, I get no kickback or benefit from mentioning this.) As we're preparing to move back overseas, my wife and I have talked about how to best stay in touch with family and friends in the US. E-mail is our primary method and I don't really see that changing -- I can write at my convenience and they can read and respond at theirs. Blogging and Tweeting are fine but they are best for primarily one-way communication or very short updates. iChat/Skype instant messaging works but that can be tedious for anything in-depth.
Skype voice works but is cheapest for computer-to-computer calling. We've used Vonage VOIP as our primary phone for the last 4 years -- they advertise as being $24.99 per month but taxes and fees run that up to $30+ per month -- still better than most landline or cell phone services because all US/Canada calls and now calls to landlines in about 60 other countries are included, unlimited, in the plan.
But, the best option seems to be magicJack. You purchase the USB dongle for $20* and for $19.95 per year, you can make and receive unlimited calls to/from any phone in the US and Canada for no extra charge (yes, that's $19.95 per year). You do have to have a good internet connection. Since most of the people we would talk to are in the US, this works well for us (assuming that our internet connection in Kenya is good enough).
The one downside we thought we would have to deal with was having to have a phone attached to our computer. But, we only have to have the fairly small USB dongle and we can use a headset or even the built in microphone and speakers in our computers. And, one dongle (i.e., one account) can be used on multiple computers so whoever wants to talk, plugs the dongle into their computer at no extra charge.
If you're looking for an inexpensive way to make US/Canada long distance calls, you might give it a try.
Run (and talk) well, y'all,
*You purchase the dongle for $39.95 but that includes the cost of the dongle and the first year's service. magicJack is offering a free 30-day trial but it's cheaper to go to CVS pharmacy or Radio Shack or another supplier and purchase the magicJack and pay state sales tax than to pay the shipping that magicJack charges.