If you're up on your cook's equipment/kitchen gadgetry, you probably know the item in question as an immersion blender. But I like my name for it better.
The version of this appliance that graces my kitchen is called the Braun Multiquick, but that's not really important. What is important is that you imagine the spinny bladey part(s) of a blender on a long handle on an electrical cord, so you can wield it into whatever needs blending. Just plug it in, put the blendy end in the food, press the button on the handle (if you like the pulse setting on a standard blender, you'll love the control this gives you), and away you go.
Not impressed yet? Try the fact that this critter comes with attachments that make it into a cool miniature food processor (excellent for mashing chickpeas into hummus, grinding fresh basil into pesto, or mincing garlic for garlic bread), or an electric whisk/eggbeater thingy. That's pretty cool.
In addition to the aforementioned applications of this toy, you might want to check out: