Like the idea of homemade butter but don't own a churn? Use a blender. As this video from the folks at CHOW demonstrates, it requires a little more effort than just flipping the switch, but it works like a charm.
The video above shows you how it's done -- all you need to do is pour in heavy cream (best if it's at room temp) and fire up the blender until the solids separate. Pour off the "buttermilk," which you should definitely save for other uses. Then "rinse" the butter with water a few times in the blender to make sure any more buttermilk comes off (it will spoil faster than the solid butter will). Once you're finished, spread the butter out over a strainer to make sure any liquid drains away, scoop up the butter, and store it in plastic wrap rolls for use.
This method is especially useful if you want to make herb butter or spice-infused butter. Add the herbs or spices near the end of the process, maybe after the last run in the blender to break them up and really get the flavour in there. Trust me, you'll love the result.
Make Butter in Your Blender [CHOW]