I would say yes to including camps on your summer schedule. We went to several camps or showcases where the morning activities just included the host schools but in the afternoon various D3 and juco coaches from around the area would come in to observe. I don't know how much people are actually recruited out of those camps, as adbono said, but it's at least an opportunity for schools further down the food chain to get a glimpse of people they probably can't afford to travel to see.
And in reply to adbono's comment about attending camps for the experience, I agree. But not just for baseball. Go in a day early and do all the stuff any prospective student would do. See the dorms, if school's in session go to a class in a possible major, meet with a professor. There's a lot more to college than baseball.