It is pretty simple... being on the radio show before, you call in from whereever you are. I called in from the office, thus the computer is on while I am on the phone.
If you can't do that, then what I suggest you do is call, and get DSL or cable. You then can be on at the same time at both. This is a new wonder just created this past 10 years or so... I remember once I had two actually have two phone lines so that I can be on the boards and talk to someone at the same time.... whoa...
It is called getting immediate feedback on the show. Such an incredible new 'technology' we got now
