If you find yourself with left over pretzels, put them in a plastic storage bag and store in the freezer.  Yes you can microwave them for about 1 minute, however this method makes them a bit rubbery.

The best method for eating a frozen pretzel is to let it thaw at room temperature for 30 min. However if you just can't wait, place them in an oven (toaster oven works great) at 300 degrees for about 3-4 minutes.

Eat them plain or squeeze some mustard on top and enjoy!