What's a slice of fruit pie without a dollop of whipped cream? Don't break out a mixer or whisk -- all you need is a jar with a tight-fitting lid and a little energy. The just-like-magic trick is perfect for parties or picnics. Kids will love to lend a hand. Here's how to do it: Fill a jar one-quarter full with cold heavy cream, then seal and shake until cream is thick and fluffy, 2 to 3 minutes.