hiding canvas items?

I draw a large number of items on a canvas, and I am interested in toggling 
their display.  For instance, if I uncheck a checkbox, all items with its ta
g will disappear, and they will reappear (rather than be redrawn) when I cli
ck the checkbutton again.  Deletion and redrawing would take up too much tim
e.

I suppose I could make them the same color as my canvas and lower them benea
th everything else, but that approach seems particularly inelegant.

Any help in figuring out what I would intuitively expect to work but can't s
eem to make happen would be much appreciated.

Anthony