There is a good discussion going on in spymac.com discussion forum in a thread started by me. It would be nice if you just go through it. Many arguments for an aginst free software and linux adoption is there. Also if you want to get an audience who don't know what linux is and who want to know what it is. It is ideal place to discuss. One important difference there is that majority on the forum use Mac OS X, very difficult to convert than Windows. they say it is secure ( It is Unix -- a BSD variant). They say it is powerful and userfriendly. It is worth signing up and join the discussions.
All Free software evangelists come out and join me in this effort.
http://www.spymac.com/forums/showthread.php?threadid=107392
Praveen A