Logitech's 15-watt AudioHub speaker system doubles as a powered USB hub. It usually sells for around $100.
Almost without exception, notebook speakers...what's the word I'm looking for...suck. If you use a notebook as your primary desktop system, you should definitely look into a speaker upgrade. TigerDirect has the Logitech AudioHub notebook speaker system on sale for just $19.99 (plus shipping). How good a deal is that? Just about everyone else sells it for $80 to $100.
The AudioHub delivers 2.1-channel digital sound (meaning it has two satellite speakers and a subwoofer) via a USB interface. It also doubles as a powered, three-port USB hub, a nice benefit for port-strapped notebooks. (Plus, if your notebook is like most, the USB ports are on the side, which makes for a lot of annoying cable clutter. Use the hub and you can keep cables in the rear where they belong.)
The speakers churn out 15 watts of audio goodness--not a ton, but better than you get from most built-in speakers. If you check the product page on Amazon, you'll see that nearly 75 users rated the AudioHub 4.5 stars out of 5. Not too shabby.
I don't love the AudioHub's aesthetic--I actually find it pretty ugly--but if you regularly use your desk-bound notebook for music, movies, games, and the like, this is a crazy-good deal on a speaker upgrade.