A type of pasta, meaning in Italian "little ears", which should give you an idea of their shape. They also look like diaphragms to me, but I guess, given the choice, I'd rather eat an ear than a diaphragm.
Orecchiette are small dome-shaped circles of pasta that usually take 10 to 15 minutes to cook, depending on the brand. Orechiette come from Apulia in southern Italy, and though they were once rarely seen outside of their native habitat, they have now become rather common. In fact, I'm eating some right now. The traditional pairing is with broccoli rabe (noded as broccoli raab, a spelling my Joy of Cooking does not include), though I have forged out on my own in preparing the dish I am consuming as I node: these are tossed with olive oil, sundried tomatoes, olives, fresh basil, and feta cheese, and they are delicious.
I didn't make my orecchiette, though. Should you feel inclined to do so, there's a recipe at
http://italianfood.about.com/food/italianfood/library/weekly/aa041699.htm,
and of course the good sneff, who I wish lived closer to me so I could eat, instead of just read about, his recipes, has a general recipe posted at pasta.
Orecchiette are apparently among the more difficult pastas to make; they are formed by cutting a small round of pasta dough and flicking it around the end of your thumb. I would guess that the size of the resulting nubbin would be dictated by the size of said digit, so little old me might make small orecchiette, while someone else might make big ones. I confess, though, that I will continue to buy my orecchiette in a box. It works for me.