A treemap is a method for displaying data by using nested rectangles. In this
case, we use a series of nested tables. A treemap begins with two or more
choices (one choice isn't really a choice is it?). Each time a table cell is
clicked on, its contents are then replaced with another table which presents
two or more choices. This process can continue until space runs out.
The neat thing in this is that all the choices that the user did not make
remain available to throughout the process (by virtue of replacing only
selected cells).
I would be interested to know what you uses you come up for it.
Usage
$(selector).treeMap(stepFunction, {...options...}) 

The stepFunction is called after each selection. The stepFunction receives the
current step, and the selected value and should return an array of values. If
the stepFunction ever returns null, then the treemap will be considered at an
end and the onComplete callback will be called.
