Peanut feeders are an important part of my winter bird feeding protocol. There are two basic types, one with larger holes for dispensing peanuts in the shell, and one with smaller mesh for unshelled peanuts.
Blue Jays love to take the whole (shelled) peanuts away to cache for later, so I always like having some available. Before I started offering peanuts in the shell, I saw maybe one or two Blue Jays a day, sometimes none at all. Let me hang this feeder, though, and within minutes, I will have 5, 6, or even more jays all at once. They fly in and out so quickly that I have yet to get a decent picture of them, but I'm trying. The ones who are too impatient to wait their turn at this feeder will come to a platform feeder to gobble up a crop full of black oil and safflower seeds, but even they don't stay still for long. For a big bird, jays are damned hard to photograph.
The jays aren't as interested in the unshelled peanuts, which leaves them for the less aggressive birds. Red-bellied and Downy Woodpeckers love this feeder, as do White-breasted Nuthatches and especially Tufted Titmice. Occasionally, I will see a chickadee here, too.
This is a better picture in person. When I took it, I still had my old, Stone-Age computer, and couldn't upload or store photos on it, so I was getting my pictures on a CD. Now, I can't find the disc that has all my bird photos stored on it, so I had to take a picture of the picture.