At my library we sign books out by hand (still!).  If I cannot locate a
pen easily, I ask the patron to borrow his or hers.  Occasionally, I
neglect to return it.  In fact, I once almost adopted a Mont Blanc pen.
In addition, my boss goes to the office of a physician friend to
"borrow" one of hsi pens (she likes the way they write).
 
In all seriousness, pens and paper will disappear no matter what we do.
Since such items are stock, at my institution we just order more.
I worry about the possible inconvenience to myself and the other library
staff.  In terms of the money, compared with the computers and other
itmes that disappear from my institution, pens are small change.
 
Ellen Rothbaum
Medical Library
North Shore University Hospital
Manhasset, New York