1) clueTip
clueTip goes one step further than (mb)tooltip, it has many advanced options that you can utilize such as having the tooltip move with the mouse cursor, forcing the tooltip to stay on the page until a user action closes it, a really nice “loader” graphic which appears between the point that the event is fired and the tooltip is loaded, and much more.
The loader is actually very useful, especially when you are loading dynamic content into your tooltip via ajax for exampl...