Wrap in damp paper towel or plastic bag and refrigerate for up to 1 week.
Freeze: To blanch, wash, drain, trim and cut the spinach. Use a wire basket, or metal strainer to lower the spinach into vigorously boiling water for 2 minutes. Immediately remove and cool by dunking into a bowl of ice water. Dry and pack into freezer bag or container.
Dehydrate: Assuming you don't have a dehydrator (if you do, follow those directions!), wash, trim off stems if desired, and pat dry. Place a single layer on a cookie sheet, pop them into your 200 degree oven for ~ 20 minutes. Keep your eye on them towards the end -- they can burn easily. They may need a little more time, so pay close attention. Once you have the timing figured out for your oven, write it down somewhere so it will be easier next time.
Crumble up those greens, and then add them to eggs, smoothies, soup, stews, sauces--whatever you can think of! Re-use one of those Parmesan cheese containers (not that you buy that pre-packaged convenience stuff!) to make it easy to sprinkle it into everything.