Referral Source Messages on WordPress

Personalization comes in many forms on the Web these days. While you may not know everything about the user(s) visiting your WordPress weblog, you might be surprised to learn that you actually have a lot more data than you think about each user session.

Here's an example of WP Greet Box and its related posts feature (based on the keyword passed from the referral source):

http://wordpress.org/extend/plugins/referrer-detector/