Some people also add parsley or cilantro to their pesto.
I would say that you could experiment with adding olive oil to it, but I'd definitely add fresh leaves too, I can't fathom a pesto sauce that wasn't made from fresh herbs. But I suppose you could create something different with your mix that would be tasty. Some people like creamy pesto, in which case you could play around with it in a sauce pan with some fresh cream and butter, let it reduce a little and add extra parmesan cheese before tossing it with your hot pasta. You could probably do a lot with your mix, for instance, mix it with a little softened cream cheese for a nice dip for veggies or toasted pita breads. Alert us of bad posts.