You need butter right now, but you forgot to take it out of the fridge. Josef Spalenka has cracked how to soften butter in the microwave without it melting. He calls it the "Toothpick Tripod Method".
My idea was to elevate the butter pat above the plate, using toothpicks as shown in the above image, to avoid contact with the plate and hopefully achieve even heating without melting.
Using the toothpick tripod method, you can simply set the microwave for any sufficiently long length of time, and then carefully watch the microwave until the buttery tripod softens and falls down under its own weight. The result is perfectly spreadable butter with no melted liquid, every time.
Spalenka notes that this also eliminates the problem of variable heating between different microwave ovens. If you don't have toothpicks handy, you could use a glass to soften butter or a zipper bag and rolling pin.
Toothpick tripod: microwaving butter without melting it [The Spalenka Letters]