Grantland's Jonah Keri took a tour of MLB's film and video archive, and got the background on a handful of clips—old-timey and otherwise—that have recently been put online. Like the one above: a 1924 instructional video featuring Ty Cobb, Babe Ruth, Dazzy Vance, and Walter Johnson.
I think it's already neat as hell that this even exists—it's 91 years old! But it's even cooler that there's enough footage from that era that we can recognize Ruth's swing, or Johnson's delivery, as something familiar. Baseball's history is its most valuable asset.
Check out Keri's piece for more gems, like video of vintage Pedro Martinez, and the archive's oldest single item, film of the 1905 New York Giants raising a pennant.