LZR suit: OK. I'm sure it's fast. But notice, in many events (butterfly, breaststroke, IM) swimmers don't wear them. I'm not sure why not (probably limits range of movement in the shoulders?) but world records are dropping even when the suit isn't being worn.

Starting blocks: I think wooden starting blocks went out in the 50s. My high school had abandoned them, anyway, in the 80s and at that point it hadn't been updated in at least 20 years. Anyone starting on wooden blocks was probably also swimming in a 25 meter pool (now known as "short-course").

Video is also not new to the sport. I suspect one can get better video today than ever before, but video stroke analysis is at least 20 years old.

What do swimmers do with those blood tests anyway? I suppose it can help dictate training and possibly diet decisions, but really, it's not like some sort of jet engine, and what it does on race day has to be pretty trivial.

Wide pools have been around at least since the last Olympics. Don't know about the fancy lane markers.

Obviously everyone is swimming in a really fast pool, but you also have a whole generation of extra-ordinarily swimmers chasing a mind-bogglingly fast Phelps. So motivation has to count at least as much many of these "technological" advances.

Anyway, all of this should be easily mathematically solvable. We ought to be able to model a Mark Spitz era pool for drag and whatnot and drop a bana-hammock-suited virtual Michael Phelps into it. Or find a real Spitz era pool (there are plenty around) and swim a real Phelps in it. I bet he'd be up for it. I suspect, actually, he swims in plenty of them every year and an enterprising journalist could probably dig up times and compare them, factoring out minor advantages in whatever suit Phelps happens to be wearing. Mr. Saletan? This is your job, isn't it?