The variety we grow at Sagebrush Variety Show Farm is called selvatica aka wild arugula. It takes a little longer to germinate than the cultivated kind, but once you plant it, it'll easily self-sow itself year after year. Even though it's supposed to be an annual, it perennializes, which means the roots don't die in the winter and grow leaves again every spring.
A good way to eat it is in a salad--by itself or with other greens--with a dressing made of olive oil, fresh lemon juice, and grated raw garlic. For a creamier variation that sticks better to the leaves, whip some applesauce into the dressing.
Arugula is also good in sandwiches or chopped into pasta salads. You can make a pesto out of it, too.
Here's a link to groovy arugula nutrition facts.
