skype...
I just had my first VOIP experience, with Skype. I am working for a consulting company and one of the partners lives in Paris. We set up skype accounts and are now scheduled to chat twice a week via the system.

The quality of the conversation was outstanding (well the sound, the content was pretty good too). The other nice feature was the call was entirely free (other than the $25 I paid for the head set). Apparently there is a feature I can also use to call non-skype users, but I need to explore that a little before I figure out if it makes better sense to use Skype or my cell phone (I am getting rid of my land-line in the next month or so).

So far I am very impressed with Skype!