View all listings in Recommend Sites . You can set a quota of how many people a visitor has to receive credit for before you are emailed. The user can also see who he has referred and how many people he has received credit for. Offers Levels as well.
All settings customizable.
Now you can let your visitors send other people e-mails extolling the virtues of your site. Not a new idea, but this script will send an e-mail, with message to the friend, send a copy to you and a thank you message to the sender. It will send a message to the email addresses you type in. You can edit the message by going to message.txt . You can edit a little in the config.cgi file.