Mike Clelland has some great sauce recipes including one for pesto.
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=27844

Arugula and Baby Spinach Pesto
from Another Fork in the Trail © 2011

Dehydration Time 5–7 hours
Makes 4–6 servings

This recipe was one of those happy accidents that happened when I was trying to use up some fresh greens prior to one of our longer trips. The peppery flavor of the arugula is great on pasta, gnocchi, tossed with tofu and vegetables, or used as a pizza sauce. I prefer walnuts in this pesto but you can substitute pine nuts.

2 tablespoons walnuts, coarsely chopped
2 cloves garlic, minced
1 1/2 cups arugula
1/2 cup baby spinach
1/4 teaspoon kosher salt to taste
1/4 teaspoon freshly ground black pepper
1 teaspoon red wine vinegar
1/4 cup extra virgin olive oil
1-inch x 1-inch x 3-inch block Parmesan cheese (optional)

At Home
Toast the walnuts in a dry frying pan until they become fragrant. Let the nuts cool and then wrap half of them in plastic wrap. Mince the garlic and set aside.
Fill a large bowl with ice water. Put a pot of water on to boil and put the arugula and spinach into a fine strainer or sieve. When the water reaches the boil, dunk the sieve into the water for 10 to 15 seconds and then put the strainer full of greens into the ice water to stop any cooking. Drain well. Add garlic and 1 tablespoon of the walnuts to the food processor and pulse until the nuts resemble a fine meal. Add greens, salt, pepper, and vinegar. Blend well. Spread the mixture on lined dehydrator trays and dry for 5 to 7 hours. Allow to cool and place the mix in a ziplock bag. Put the walnut bundle in the bag with the dried greens. Wrap the Parmesean cheese, if using. Add the olive oil to the other oil you will take on your trip.

At Camp
Add 1/2 part water to 1 part dried mix and allow to rehydrate, adding water a little at a time if necessary. Add 1/4 cup of olive oil to the bag, close the bag and knead with your hands until combined. Shave the Parmesan cheese, if using, with your knife or cut into small pieces and crumble with your fingers. Add the cheese and nuts to the bag and mix again, or, if you are having this with pasta, toss the pasta with the pesto and sprinkle the cheese and nuts on top.

This looks pretty tasty!

Laurie,
If I used basil instead of arugula and spinach would I still have to put it in boiling water?

I don't blanch any of my greens when I make pesto (including spinach and arugula), I think it might come out slightly more bitter. When I use basil it comes out less bitter. I would see no reason to blanch basil.

now... if I was to use stinging nettle... that's a different story

Thanks Ben.

I make spinach pesto often - I leave mine raw as well. More vibrant tasting than when cooked :-) I do the same with kale.

The blanching helps with color and gave the flavor I wanted however you can skip that step if you wish.

A note about fresh basil... I wouldn't blanch basil as it is too delicate for that but... wash basil while it is still on the plant/stems. Why? If you wash it once you pick it and then dehydrate it, the basil will turn an unappetizing color of grayish-brown. For some reason it doesn't do this when you wash it while the leaves are still on the plant and let it air dry. It's very strange.