Demo Updated (8/29/2007): In addition to the image lightbox demos, I added four more types: text content, web page, web page with video, and embedded video. Check it out.
Yahoo! User Interface Library (YUI) provides a very handy class for creating modal dialog box with background masking, which can be used to create lightbox. If you have no idea what a lightbox is, you can run this online demo to get a taste of what it looks like.
There are several advantages to use YUI to create lightbox. The most important one is you get cross-browser compatibility support out-of-box. The above demo has been tested in IE 6, Firefox 220.127.116.11, Netscape 8.1, Mazilla 1.7 and Opera 9.21, which was created without any hacking. Another hot feature is that one can easily create a drag & drop lightbox without any extra effort.
I am making an Ajax application using GWT and I need some kind of facility to display a tooltip on an image when I hover my mouse over it. Unfortunately GWT does not provide such widget that I can use directly. After spending some time on GWT forum, I found two neat posts (refer to post 1 and post 2), which included some source code for making tooltip widget.