@Thomas,
Sure - that is, if you like walnuts. I make a parsley walnut garlic olive oil pesto instead of the usual basil pine nut garlic olive oil, both having parmigiano (or whatever) added.
This one adds basil too, while I don't usually:
http://www.recipeview.com/recipe/227761
One can put a lot of pesto on a relatively small amount of pasta..
Pesto freezes well, but I don't add the parmigiano (or pecorino romano or asiago..) until actually using the pesto. The first time I ordered pesto was not in italy but in Sonoma, and I was amazed how
green the dish was. It was a huge dish for a luckily hungry person - I ate the whole thing. At this point I don't usually look up a recipe, just add some of this and some of that.
There are sage pestos, cilantro pestos, and probably others out there.
I like it on pasta, but if you are pasta avoiding, I suppose it could be a good dip (green beans? battered veggie fry?).. or... bloom into a soup of some sort. Thinking, veggie broth, potato chunks..