The lost key retrieval service is at http://www.grlevelx.com/lostkey — you must have access to the email you originally purchased the software with. This is also why Gibson Ridge (and our group) strongly recommends saving all emails from the time of purchase, including printing them or saving the emails in a mailbox folder or a way where it can be backed up.
GREarth/GRModel users: your AllisonHouse login info is all that is needed.