If you need to soften some butter for baking, one way to speed the process along is to grate the butter using a cheese grater. This will increase the surface area of the butter, and it will soften much quicker.

You can always try using the microwave too. But whenever I try this, I find that the softening is very inconsistent and the butter is watery in some spots while still hard in others. If you use the cheese grater, you get better consistency in the butter.