This latest library (as the screen-shot best presents) supports for an attractive message box (I think it’s attractive anyway). I designed the PNG icons myself so there should be no rights issues and everyone is free to use them as they wish.
To customize your message boxes modify the message-box.html and message-box.css files, for documentation see the message-box.js and message-box-setup.html files.
The download contains a message-box-setup.html file, open/view this for the demo. Tested in IE 6/7, Firefox, Opera and Safari.
I have also made quite a bit of progress on the iido application over the last few weeks, and will post a blog about it (including a short video) for early next week.