This is probably going to get me a ticket on the crazy train, but I actually like the process of hand-whipping cream to make my own whipped cream. Unfortunately, after a bad work relationship with a poorly designed computer mouse, my wrist doesn't enjoy the process quite so much. So I use my stand mixer.
The Mastrad Qwik Wisk ($19.99) gives me another option, particularly for small quantities. The Qwik Wisk holds a bit over a cup, making it a good choice for a few small servings of whipped cream. It operates with an up-and-down motion, with two spinning disks doing the whipping in the enclosed container. You can also store the finish product in the container; the rubber base of the whipper comes off and becomes a lid.
I tested it first (and second and third) by making whipped cream, and it did a fine job—just as good as I'd get from using a whisk and a bowl but less messy.
Next, I made salad dressing, followed by mayonnaise. I was particularly pleased with the mayonnaise since making that in small quantities can be annoying. With too few egg yolks, a standard blender won't grab the yolks to beat them before adding the oil, and a stand mixer is overkill for a small job like that. Since the Qwik Wisk's lower disk reaches all the way to the bottom of the container, it had no trouble grabbing and whipping a single egg yolk, and it had no trouble incorporating the oil, even when I glugged it in a little too fast. And, since you're doing this by hand, you can feel the ingredients thicken as you whip.
While this wouldn't be useful for someone who makes whipped cream by the gallon and mayonnaise by the quart, it's quite useful for someone who wants to make a cup of whipped cream or mayonnaise without dirtying a big bowl in the process.
Like many kitchen gadgets these days, this is another that would be great for kids who want to help in the kitchen since the motion is simple and the mess is contained. It's also great for folks who have lost some manual dexterity.
And, another plus—it's kind of fun to use.
Disclaimer: Testing samples were provided to Serious Eats.