How do I make jpeg image background transparent?

[handrawn]

and you could try Mark McLaren's macs white filter - one click removal of white
works with my photoshop, and painter too, though not of course on the background layer


http://pspug.org/filters/filtersff.shtml

PS I dont think you can save jpg transparent either - png tif tga, gif of course if 256 colors ok, but not jpg?