In response to Janie Branham:

I have been experimenting with this very problem for a little over a
year now.  What I have found to be most successful is a combined
approach.  First I triage the discards into items I feel are 1) useful
to other libraries or dealers, 2) items I can give to the local prison
(popular or well-illustrated) and 3) items that are too obscure or
ephemeral to be in either of the other categories.  The third
category gets recycled.  The second category gets picked up.  The
items in the first category I enter into a spreadsheet listing title,
ISSN, volume, issue, and date.  This can easily be edited and sorted
for specific purposes.  Since most of my material was engineering-
related, I worked with the Engineering Libraries Division of the
American Society for Engineering Education to set up an electronic
Duplicates Exchange on the internet.  Over 100 members get lists
from me and can get me to post their lists for them.  Usually, I get
from 1 to 4 requests for items from such postings.  After letting my
fellow librarians get first choice, I print up three copies of the full
list that I send to used journal dealers.  When one makes me
an offer, I check with the others to see if they care to bid on these
items (they tend to want the same materials).  When the bidding has
finished (this step can sometimes double the amount of money that I
am offered!), the remaining items on the list are offered to USBE
who pays postage on items that they can use.  I find that, although
this is labor intensive, it makes maximum use of our duplicates with
a high return and good distribution.  The items left in category 1
finally get sorted into prison or recycling after 3-6 months.
Sometimes I get gifts of long runs of older issues of journals  that I
do not need and cannot be disposed of in the above manner.  I have
found postings on USENET Newsgroups to be a great way to find a
good home for these items that are not needed by librarians or
dealers.  These newsgroups put you in direct contact with the
practitioners, who often
want backruns for their personal collections.  I have often found local
people who will pick up the items.  I have even found people willing to
pay the shipping for large sets (I do require postage to be prepaid
when I am dealing with individuals).
I have not used the ALCTS Duplicates Exchange Union because it is still
paper-based and has over 500 members.  This means that I would have
to send out over 500 copies of each list, and then review over 500 lists
per year from other libraries.  The cost and volume of work in doing this
has kept me from trying it.  I would be interested in hearing from others
who are involved (all 500+ of you out there!) to seeing how well it works
for you.
Overseas shipments seem to be hard to work out.  It seems you need a
group willing to organize the details and pay the postage, and I have not
been lucky enough to find someone to handle both these aspects.
I appreciate this opportunity to discuss my findings.  I hope to hear from
others as to what is working for them.

Orion Pozo, Collection Manager
NCSU Libraries, Box 7111
N. C. State Univ., Raleigh, NC 27695
internet:  orion_pozo@ncsu.edu
tel: 919-515-7557  fax: 919-515-7854