Integracer02, in the past working with other companies on presentations, I simply e-mailed my questions and they were happy to respond publicly to all questions.  I see no need for me to call during the presentation, but if you prefer that method then go ahead.  To be honest, I have seen lots of problems with poor connections or cell phones going in and out or poor sound quality when people phone in.  As JB knows, I have no problem at all with calling, but I prefer not to.  I have been both a top manager and Corporate Director and the last thing I wanted during a presentation was to be bushwhacked with a question out of left field.  This is why I try to gain consensus on a set of questions, and submit them in advance so the speaker is prepared to answer them.