Needed a quick carb to accompany reheated Eggplant Rollatini and didn't want to open a big jar of pasta sauce, so I added some already open salsa to sauteed onions and garlic. With some grated parmesan it turned out to be a perfectly acceptable sauce for penne with an alternative taste to the usual standard Italian fare. I don't suppose this is news to anyone but an inexperienced chef like myself, but I liked the result of the experiment.
Funny I made lunch today along those lines--chopped salad with red leaf lettuce, chicken, red peppers, corn, black beans, salsa, pasta, ... The pasta was an afterthought because we had some leftover but it was a nice addition.
When I was in college, I used to collect those Taco Bell red taco sauce packets and use them as "pasta sauce" on my rigatoni.
James Beard recounted the same story in his book, "Beard On Pasta." All he could scrounge up one evening after testing recipes was a tub of salsa. He says it was some of the finest eating ever, cold salsa on hot pasta.
After reading that, I now make cheese tortellini and mix it with salsa and eat it as a cold "salad" type side dish.