iBooks,
like just about all computers, have a stereo Sound Out port. Almost
all speakers can hook up by this type of port. Considering the
iBook only has a single, mono speaker, you're probably going to
want something better. Be it headphones for quiet travel, or a
pair of 12ft. speakers to blow the neighbors away, its up to you.
If you want to listen to CDs with it, have games with excellent
sound that other people actually doing work around you might be
annoyed by, or just hate the slightly tinny sound your built-in
speaker gives, external speakers are probably for you.
