Yes, that's right, free! I often tell my kids that there's no such thing as a free lunch, but I have to admit that Skype is about as close to a free lunch as you can get. Imagine this, free calls to anywhere in the world with free instant messaging, plus no annoying ads or spam. It's free to download, and once you are up and running with your own user name, you can call anyone with a computer who is also connected to Skype. If they don't have a computer you can still call them with the Skype-Out service that is much cheaper for overseas calls than a regular call. For example, to call Canada it's 2.4c / minute compared to 59c with AT&T from your cell phone. Even text messaging is cheaper, for example 11c / message to the UK compared with AT&T's 25c.
So what do I need?
First of all, a computer. Skype is not a particularly demanding application and will run on most PC's and Mac's. You will need a microphone and speakers. Some modern laptops have these built-in and work quite effectively, but for the best voice quality I reccomend a dedicated USB headset (like headphones for only one ear with a microphone that expends in front of your face). If you want to video conference you'll need a video camera but again, most modern laptops have these built-in and they work very well.
The biggest factor in using Skype is the internet connection. If you have a cellphone aircard these can be used very well, especially in urban areas supporting 3G (the fast network), even for video conferencing - I actually get quite a kick out of using my AT&T aircard to call the UK while AT&T doesn't get a penny for my call - serves them right for charging so much!
You can use your campsite WiFi connection, but in my experience this can be very variable. If it's a modern campsite with fewer guests you'll probably be OK, but older parks with slower connections will be more problematic and you can forget video conferencing.
Satellite systems while they provide the necessary bandwidth have significant latency as the signal has to travel so far - it's more like talking to someone on a CB radio than a telephone. Duplex (both people talking at one doesn't work well), but with practice it is possible and if there is no cell phone service can be a useful last resort.
One feature that I like a lot is the forwarding feature. With this feature set I can have my Dad call me from his computer in England for free. Skype then forwards the call and I pay (a nominal charge) for the connection to be forwarded to my cell phone. You can even make free Skype-to-Skype calls from your iPhone, how cool is that?
So there you have it. If you have family or friends overseas, want to video conference, or just reduce the minutes on your cell phone plan, Skype could be for you.
[Remember that Skype is not a replacement for your ordinary telephone and can't be used for emergency calling]