These days a lot of computer monitors come with speakers included - but it's hard packing quality sound into increasingly razor-thin bezels and frames, so generally the results won't blow you away. If an upgrade in sound is in your future, then external speakers are an easy option.
The Orbs: These round beauties follow along the lines of the popular Orb Audio Home Theatre system - but are small enough to plug into a laptop. A good example? NacSound's Geminos Speaker System. Developed for European Apple Stores, these globes are a sizeable 9.5" and have Magic Touch controls to adjust power and volume. There is also a smaller, state-side option in the Siig SoundWare Sphere Speaker System or a more alien-pod egg shape (and USB powered) alternative in the Olasonic TW-S7.
The Squares: No stodgy even-sided boxes these; rather a re-imagining of how effective simplicity can be. Take the BassJump 2, which is fairly straightforward to look at, then consider that this portable subwoofer turns your MacBook into a mini-sound system. Similarly, the TangoBar is designed to be heard, not seen, as it sits innocuously under your monitor.
Or, perhaps consider the Speak-er, a clever thought bubble/ speaker combo that makes a statement. SMK-Link's GoSpeak Pro Ultraporatble's are just that, easily zipping into a carrying case and connecting to computers, CD players or iPods alike. Looking for something thin? Insignia's Flat-Planel Portable Speakers should help save space - both on your desk and during transport.
The Class Acts: Philips' Multimedia Speakers 2.0 are a breath of fresh air; the white body and yellow trim liven up the standard black offerings - the speakers themselves can be used to charge cell phones and MP3 players. Speaking of double duty, Zalman's sleek, reflective ZM-NSP100's can stand on their own or be clipped to your monitor in various configurations, making for easily customizable sound. They also come in a bright white/lemon yellow combo that draws the eyes as quickly as the ears.
But Audyssey's Lower East Side Media Speakers might be the crowd favorite, with a sturdy black body and sleek red accents, these speakers are a looker for sure, but they are also capable of a bass-y, solid sound. Likewise, Altec Lansing's FX2020 Expressionist Classic speakers are thoughtfully designed with squares smoky glass supporting a solid speaker body full of big sound.