Dynamic help baloon type feature

Dynamic help baloon type feature


I am not even sure what is the right term for this kind of
functionaly.
If you go to http://www.netflix.com/BrowseGenres/New_Releases/gnr?lnktrk=GID_NR
and take your mouse to the right most picture then a balloon appears
on the left side of the picture. If you take your mouse to the left
most picture then balloon appears to the right of the picture.
I need to implement something similar for a caledar event so that on
mouseover the event details appear at the right place.
I am looking for an existing plugin or example that dynamically
calculates where to display the box. I would try to learn from this
plugin/example.
Thanks