Salted peanut shells will attract deer to your compost pile if they are in your area. My deer play king of the kill on my compost pile. Not too much of a problem unless you have a thing for neat high piles.
Peanut shells might make a very good mulch/ammendment to your tomato patch (if deer are not a problem). Low levels of sodium in the soil improves the flavor of tomatoes (scientific study, not old wives tale), and the high lignin content of the shells would slow decay such that nitrogen robbing (robbery?) would probably not be a problem, and the cupped nature of the shells would keep the soil from compacting.