As you can see, I have this setup on my piano. This is great for working out songs and puts me in a great near-field listening position.
The prices are always moving up and down on these items, but you can usually pick up the speakers and amp for around $65 or less... sometimes much less.
Along with the Amazon links above, I'd also check out the items on Parts-Express and Monoprice.
Infos #1: Skip the weak 12V 2Amp power supply that comes with the amp. Get a Replacement 60W 12V 5A Adapter Charger for Benq LCD Monitors ... it is a 12V 5Amp power supply that actually gives you all the power the amp is designed for. I went over a year with the original power supply and was satisfied more or less. But the amp would clip and momentarily shut off if I pushed the volume too high. With the new power supply, no problems and sounds even better.
Infos #2: There is an entire community surrounding this speaker/amp combo. There write ups on how to upgrade the capacitors in the amp for even better sound and performance. Apparently, the capacitors that the amp is built with have a quality control issue. Sometimes you get good, sometimes you don't. I am currently happy with what I got, so haven't pulled apart and rewired yet. Maybe later. I suspect though that we're getting into the very fine details on specific sound details.
Infos #3: I'm a musician and a low grade audiophile, and while I can personally attest to the good sound that these speakers put out, why not take the word of a professional? Steve Guttenberg knows what he's talking about.