[ANN] Snap to grid for Draggables

Heya,

Following an idea from Saimon (http://dev.rubyonrails.org/ticket/ 
2826) and
Borlum (http://dev.rubyonrails.org/ticket/2583) and possibly others,
script.aculo.us Draggables now sport a new "snap" option that works  
like this:

snap:25
snap to a 25x25 grid (0,0 is at the elements 0,0 coordinate)

snap:[10,25]
same as above but with different x/y grid size

snap:function(x,y) { return [x,y] }
do-it-yourself grid implementation

The latter can also be used for stuff like constraints, for example:

snap: function(x,y) {
      return[
        x<100 ? (x > 0 ? x : 0 ) : 100,
        y<50 ? (y > 0 ? y : 0) : 50];
    }

will constraint the dragging of the element to a 100 by 50 box
(not calculating in the element's width or height).

With some more tinkering you can implement some pretty advanced
stuff, like basing the snapping/constraint on the current position of
other elements.

Hope you find that useful!  Comments are welcome!

Cheers
Thomas