What should you expect from a "multimedia" speaker that costs $20? Well, for starters, no stereo sound, because the Logitech Z50 is a single speaker. And not something that delivers deep bass because the Z50 is pretty small -- about the size of a coffee mug sliced off at an angle at the top, with only one upward-firing driver. And, no, don't look for wireless capabilities, either.
On the plus side, the speaker is fairly attractive (it comes in three different color options), is very easy to set up and use, and due to its pencil-cup look, seems at home on an office desk.
To get going, you simply plug the small AC adapter into an outlet and then connect the the hard-wired 3.5mm audio line to your computer, smartphone, or tablet (or any other device that has a 3.5mm audio output or headphone input). The Z50's specs say that it has 10-watt peak power, which is pretty potent considering its small footprint.