WhatsThis Tooltip Plugin.
Minor Update: 2.1 Feature added - self trigger for triggering the tooltip on image and contianer elements instead of adding the trigger.
Major Update: 2.0 The tooltip plugin now hides the tooltip box when mouseout of the tooltip box instead of the tooltip trigger. This allows you to add links and elements that the user can interact with while keeping the tooltip box open. The tooltip box adjusts the fit inside the screen if your triggers are close to the edge.
2/7/2012 Critical Update - Script linking/coding issues.