In April 2006 GNU Eprints (free IR software) added a request button for copies of the eprints seen in the IR. The functionality of the button allows authors to gage the level of interest in their creations. Many hope the level of interest shown will encourage authors to open the access.
"Where a record of a stored eprint tells the user that an open access copy is not available, a form box appears inviting the user to paste in their email address and send a request to the author for a copy of the paper. This request is emailed automatically to the author, offering three choices in return: to email the requested eprint, to reject the request, or to make the eprint open access in the repository." - from the press release