You might like to check out the Distributed Proofreading project
http://www.pgdp.net/c/ . I seem to recall that there was a way of installing a copy of this on your own server, which would allow you to get multiple bodies involved in the validation part of the OCR work.
http://www.pgdp.net/phpBB2/viewtopic.php?t=21864 seems to cover installation