A friend at work showed me Gabbly, which is an AJAX IM-chat pushlet that gives the appearance of putting a chat window over the top of any web page you choose (kind of like gmail-chat).
Odd thing is, it even worked for us when we set the URL to a secure wiki page inside the company firewall.
We promptly exited our Gabbly session and began chatting about it on Groupwise Messenger (our company standard). The whole experience was freaky and left us with serious security worries. Especially when Firefox crashed on me within minutes of leaving the Gabbly-iframed page.
The thought of people using a 3rd-party-hosted chat app like this at work scares the hell out of me.
But that's the trouble with things like shorttext.com, ajaxwrite.com, and other free-neato-trendy AJAX "services": They require you to rely on the trustworthiness of the host. I put it too delicately. These are man-in-the-middle applications.