Caramelized onions freeze well. Lay them out thinly on a cookie sheet, freeze, break into small pieces, and put into a ziploc so you can pull out a piece or two when you want to throw them into something.

As for what to do with them, I'm fond of putting them into thrown-together soups and stews, not as a focus but as a simmered-down part of the dish: They add a ton of savory flavor with a touch of sweetness, helping turn the water into broth. Or beef up (ha) pre-made broth with infernactual's French onion soup recipe. I haven't made it in a while, and I really should...

I loved caramelized onions in a salad with arugula, corn, tomatoes, fresh herbs and whatever else is in your refrigerator. They are also great on potatoes and burger or hot dog type sandwhiches(although I personally substitute tempeh.)

You can easily turn it into a great French Onion Soup. And given the weather, it's a perfect treat. Just add a cube or some organic beef broth to the onions with some water and let it simmer for a bit.

Then get some gruyere cheese, some bread.

Put soup in oven-proof bowl, put bread on top, grate gruyere on that... broil until it's just barely crispy and bubbling.

Oh My God pissaladiere hands down! You can use a store bought pizza crust or make your own pizza dough, brush it with olive oil, coat the crust with onions, dot the thing with oil cured black olives, anchovies (yes I said it) arranged nicely and sprigs of thyme ( or leaves if you prefer). Bake in a hot oven preferably on a preheated pizza stone. Its one of the reasons your on this planet.

make some pizza with herbed goat cheese, sun-dried tomatoes, spinach and lots of onions and garlic! I like the pizza dough from trader joe's.

Ah, what you want is mujadarah, a classic Middle Eastern pilaf of rice, lentils and caramelized onions that is much more than the sum of its parts. Here is my recipe: http://www.herbivoracious.com/2007/10/recipe-mujadara.html