I too would hope that plagerism should not be a concern unless proven.
    What is the difference between getting a hard copy or getting an
electronic copy in terms of plagerism?  Someone desperate enough to
plagiarize will be desperate enough to get something retyped and anyway, with
scanners so prevalent and simple to use, everything can become electronic if
you want it to be.
    Here is my suggestion.  Authors willing to provide electronic copies
would bring 5 or so hard copies to the conference.  When the abstracts are
printed in the program, put the authors e-mail address next to their name.
(Yes, I know their e-mail is elsewhere on the site but this simplifies
things.) When you get home you simply e-mail the author and request a copy
which can be attached to a return e-mail.  Quick and simple.  For most
systems we're talking about hitting reply, attach, clicking on the file and
hitting send.  I can do it in 10 seconds so I'd bet that most of you could do
it in 5 seconds. The recipient reads the paper and prints it only if they
wish.  Trees are saved and everyone has access to everything.
    If an author does not wish to provide an electronic copy they would
indicate as such on a new box to be created on the submission form and the
heading of the abstract would also so indicate.  That author would bring
their 25 copies and they are not affected.
    This would also solve the problem of tracking someone down from another
session that you couldn't make due to conflict yet you desire a copy of their
paper.
    I'm not a computer whiz by any definition but isn't it possible to embed
a read only command into a document precluding alterations (or maybe a
non-erasable watermark)?  If not, it would be a good idea so lets invent it
and make millions.  ( I will be retaining a copy of this letter.)

Mike Katz