Net Enhancements, Inc.
Are Dialspree Internet Phone handset products still available for purchase?
No, the product line has been discontinued.
It connects to your PC, specifically, to the microphone and speaker jacks provided by your sound card.
You can call either.
There are many PC-to-Phone services that offer low-cost calling to a regular telephone line.
Yes. An extra speaker jack is provided so that you don't have to swap cables when you make a call.
You simply can turn down the volume on your speakers instead of unplugging them.
Yes. Because the handset's speaker and microphone are acoustically separated, you can carry on a full-duplex conversation without echos.
Unfortunately, no. The sound card connections for the MacIntosh are different from the PC standard.