ebay list them for free, start the bids at 1$
and donate all the proceeds through ebay's
"giving works" they have like 1.000,000
charities from food banks to shelters to
boots on the ground in the developing world
( and if your favorite charity isnt' there, get them listed ! )
you can get a usps account, they will send you boxes for free
you can print out the postage on your ink jet printer
and your mail man/lady will take it away without you leaving your home, and the
ebay buyer pays you for your shipping costs ebay puts charity listings at the top of every page
and as far as i know, the $ ( less shipping ) goes directly to the charity ...
without ebay taking a cut ... or sell the stuff on your own and just mail the $$ yourself.
i have done this for IDK 5-10 years and donated between $$$ to local food banks
as well as disaster relief selling photographs like this, i am sure gear would sell well too.
locally i am lucky, if i have gear to donate ( read: tv quality ( 1990s ) video gear, whole silk screen studio &c ) ...
we have a local artist group that loves getting "stuff" called AS220. maybe you have a similar arts group
that does hella-public outreach, provides inner city kids and regular people with art, studio, lessons, a place to be creative/pwer-spot.
good luck !