I continue to be amazed how many people don't know what SIP is. Or, put another way, how to make very inexpensive calls over the Internet. While SIP stands for Session Initiation Protocol, that is pretty unimportant to what I am about to say.

SIP is a standard for establishing calls over the Internet. The trick is to use SIP to make inexpensive calls. Not like Skype which is proprietary and expensive but open and cheap. I am going to point you at one particular vendor, http://callwithus.com, but I am just a satisfied customer of their service. There are lots of other companies providing similar services.

Callwithus and other companies offer a way to connect from the Internet to POTS, plain old telephone service. That is, by running some software on your computer or purchasing a SIP phone you can connect over your Internet connection to regular telephones throughout the world. Many companies, including callwithus offer what are called DIDs, basically an inbound phone number. Thus, people can call you from a regular telephone.

You may be wondering why SIP instead of Skype? The best answer is that SIP costs a lot less. For example, calls to Canada with callwithus are $.005/minute. Calls to the US and a few other countries are all less than $.01/minute. And, like Skype, on-line calls within the same provider are free.

While calls to all destinations are not dirt cheap that is the trend. For example, while calls to Nicaragua are still $.12 or more a minute, calls to Costa Rica are under $.04.

Does its use have to be geeky? No, not at all. There are lots of free programs to use SIP. Such software is included on my Nokia N800 and N900 smartphones. You can also purchase what look like standard desk phones and hand-held units which just work. No computer required.