Barnacles requires an invitation to join and is currently (April 2016) quickly accepting requests on the form below. (It's less trouble than trying to disable to invitation system that was mandatorily built into the site this code came from.)
Quickest route: ask an existing user to invite you (it's on their settings page, accessed by clicking their username in the header). Otherwise, make a public request below. This will display your name and URL to all other logged-in users who can then send you an invitation if they recognize you.
Your e-mail address must be valid and confirmed by visiting a URL e-mailed to you before your request will be displayed. Your e-mail address will not be shown to any other users (except moderators).