Have you ever used your laptop as a portable media player or hooked it up to a projector for a presentation at the office? If you have, chances are you also strained your ears to listen to the weak sound trickling out from the underpowered speakers. Want an affordable and portable solution? Then try the B-Flex 2 USB speakers from Jlabs.
The tiny iHome iHM77 Capsule portable speakers blew away my expectations the minute I plugged them in to my iPhone. The speakers can fit in your pocket, but are louder than any internal notebook speaker I've heard and deliver more sound per ounce than any portable speaker I know of.
Built-in speakers are generally lousy, making headphones or external speakers a necessity to really enjoy your notebook's multimedia features. Most speaker sets require an AC adapter, but Logitech's V20 notebook speakers draw juice via USB, which makes them completely portable.