The problem with using the magic wand to crop the background, is that you are gonna get a very harsh edge on the image, that will be VERY visable depending on the background color of the page it is going on ...
(This image's background was cropped with the magic wand)
If your sites' background is a light color you might get away with it ... but not the dark ones !! If you want a quality design, you should not skimp on it ... use the eraser tool !!!
