We bought my Grandmother in another city a webcam with an integrated microphone, and several of my other family members have started using it as well. There are usually a few of us online in the evenings, and we've had conference calls just to touch base. We've even used it to call people that live locally just because it's so convenient.
The VOIP software like this isn't new, and many of the features like video chatting have been available in other clients like MSN Messenger for years. The difference is that the simplicity and quality seem better, and the ability to call into traditional phone lines increases distribution.
Furthermore, from a privacy perspective, it's reasonably secure:
Skype uses encryption of a least 128 bit block chippers to encrypt communication between users, making it hard or even impossible to decrypt the content of these communications. Skype's encryption is on by default, cannot be turned off and is transparent to the user. These fundamental design decisions have removed many of the challenges presented by Public Key Infrastructure and have enabled the regular use of encrypted communication by the general population. So far there have been no known, major attacks on the Skype network.
I haven't tried any of the mobile versions yet, but it's available for Java cellphones, Blackberry PDAs, and iPhones. This means that if you're in wire zone, you can make calls at Skype prices via your mobile phone. I can't wait to try this - I'm tired of paying an arm and a leg for calls home from another city, and I usually travel to places with widespread wireless access.
Now that I've started using Skype, I'm starting to reconsider having a home phone at all. It seems a little unnecessary when my wife and I both have cell phones and we make our calls from the computer when we're at home.
I've been following a company called Truphone that's all over Skype on iPhones.
They will soon be launching Skype calling and IM on both the iPhone and the iPod touch apps. This means that you will be able to use Truphone to make and receive Skype calls and instant message.