true. based on how intricate the object is (just try getting all the stray hairs knocked-out and you'll know what i mean!!) there are a number of different methods. the most common one is to make sure the object is on it's own layer (not the background or all you'll do is make the background white) and use the  polygon lasso tool to click around the shape and delete the background. (if you completely click around from beginning point to end point closing in the object you'll need to invert your selection or you'll be cutting the actual object and not the background).

another method is to use the "extract" tool drawing around the outer edge of the object, filling the outlines shape and hitting the extract button. i don't often use it myself but it's a quick trick.

if you can do as shane suggests, and post the pic i'm sure everybody will give some good suggestions.