This new plugin “WP Greet Box” welcomes any new visitor with a customized AJAX greeting message depending on their referrer url. For example, when a Digg user clicks through from Digg, they will see a message reminding them to digg your post if they like it. Another example is when a visitor clicks through from Twitter, they will see a message suggesting them to twit the post and follow you on Twitter.
You are free to add/edit/delete/disable these messages as you choose, even the ability to set a timeout to forget a visitor so you don’t keep nagging them with greeting messages.
Referrers installed by default are blinklist.com, blogmarks.com, delicious.com, digg.com, diigo.com, facebook.com, flickr.com, furl.com, google.*, ma.gnolia.com, mister-wong.com, myspace.com, netvibes.com, newsvine.com, reddit.com, search.live.com, search.msn.com, search.yahoo.com, simpy.com, stumbleupon.com, technorati.com, twitter.com and youtube.com. You can easily add more websites if it is not on the list!