Originally Posted by janiebegood
I did this just yesterday! Plug the Kindle Fire into the computer via the USB cable. Find the video you want to load (I was moving .mp4 files, so I don't know what other ones it will support). Pull the video into the Pictures folder on the Fire, NOT the Video folder. When you're done, disconnect and open the Gallery icon. Your videos should be there.
Aaaa-HA! That explains it. I was foolishly drag/dropping my videos into the Video folder, d'oh!
(thanks for the tip, janie!)
FWIW, I loaded a DLNA streamer app called Spitka and I was able to stream .mp4 and .m4v format files on the Kindle Fire. I need to do more experimenting to see what else is supported. I'll post back here when I get some results.