I may not be able to locate a mobile friendly, PDF format online.
In case you do not know this, Adobe has a PDF reader especially customized for mobile use which re-formats any available PDF file for mobiles.
It's available here: _http://www.adobe.com/xx
you have to substitute your location/language like 'en', 'es', 'fr' and the like; mine was 'nl' for dutch, but that wouldn't work for anyone outside the dutch speaking market.
Another option would be to use Opera mini as browser, which seems to have special features in this regard:
I have to caution you though, since I myself do not use any mobile devices and I have no direct experience with any of these two options.
Edited to add:
As for the subject matter itself, I found a 45 Min's presentation from Michael Collins Piper himself about his JFK book here:
Googling for the book (authors name + title + PDF) gave me several sites where you can download the book in PDF format.
But again I have to caution you; before downloading you might want to read this topic first: http://cassiopaea.org/forum/index.php/topic,10791.0.html
Hope this helps a bit.