well, I'm pretty sure either Satchel Paige or Minnie Minoso are the only ones older than me. As for younger, I think, without looking it up, it was Mike Morgan. He was in high school with a guy a class behind me in college and went from high school to the pros.
Edit - looked it up. Misunderstood it. The last player older than me to play was Julio Franco. I was onto something about a high schooler making it straight to the majors being the one who would have been younger than me, but it turns out to be Brian Greer, who was born on May 14, 1959 and made the majors in 9/77.