Code: JavaScript

Here's some free JavaScript code...

DLjax: A friend of mine wrote this in about two minutes and it's really what I would call effectively SEO'd JavaScript. If you're stumped on how this implementation makes for crawlable text, you can always hit, "view source."

Rickroll: The infamous rickroll for you to put on your own server. You may even get a link out of it! :)

100% Height IFRAME: Place the script just below the closing <iframe> tag to make it auto-adjust to the height of the page..or something.

Change Title Tag: Place the script on a page to change the Title tag after the page has loaded.