Depends whether you just want to hear stuff, or you are really looking for quality.
I discovered pretty much the cheapest set of 'active' speakers in an unlikely place this week: DisChem, where you can buy a very convenient travel 'pouch' with stereo speakers and a small amplifier powered by 2xAA batteries, for something like R79. Great for listening to podcasts etc from your MP3 player while moving around the house or travelling. Takes input from a standard 3.5 stereo jack.
Terencek and sanimoyo: I'm a professional video editor, and would like something decent and sturdy. I would definitely get me some of those DisChem speakers for when I'm traveling Terencek. I'm looking to spend in the region of R2500. I would rather get two separate speakers for the left and right side of my monitor sanimoyo.