Data is submitted by email to the webmaster; a script will process it and add it to the "visitor page" for later display. Your email address will not be displayed, and I will discard it as soon as your entry is processed. (unfortunately you must take my word for that)
DO NOTE! I check all guestbook entries before transferring them to the site. Attempts to insert spam, obscenity, or personal attacks into the guestbook will fail, and will be reported to your ISP as abusive behavior. This checking also takes time; don't expect your entry to appear immediately.