There were some intriguing views inside the Falcon 9 2nd stage fuel tank, during the CRS-4 launch. They showed brief segments as the depletion rate got faster & faster. Right before exhaustion, the blob stopped dropping & floated up in weightlessness, like a goo. There's no reserve in those launches. Kind of scary to see a giant webbed blob of fluid slowly floating towards you through the air, as if commanded by a mind of its own to drown you.

Falcon 9 fuel tank cam (0 min 46 sec)

Fuel tank cams are useful for showing the amount of actual reserve compared to the predicted reserve, how well it's settled on the bottom for an engine restart, how much it sloshes. Bonus footage: a timelapse of another launch

Falcon 9 OG2 timelapse (0 min 41 sec)

Refined kerosene in free fall...how neat!

Many folk still think there is a 'Zero G' room run by the government.
There is a Drop Tower facility at Glenn Research (formerly Lewis) in Cleveland for small experiments. The 'Vomit Comet' is the other method of vetting/certifying experiments for use at free fall/microgravity.

Space stuff is cool...way cool.

-=Doug