We're currently finishing a library "FlashyCapito" which allows players to capture gameplay video of Flash/AIR games and share it to Facebook.
We think it might be a cool way to engage more people in games, like sharing the actual recording of their best gameplay instead of merely posting "Joe has scored 50000 points in a game of XXXX". And obviously making recording gameplay videos accessible instead of having to use specialized software.
We're aiming to make it easy to implement (few lines of code).
Shortly some techical stuff(you can skip):
The library handles the encoding using its own encoders compiled with FlasCC(aka "Alchemy 2") for web / natively compiled for AIR.
Facebook sharing is also integrated in the lib. It is 100% client based solution, meaning you don't need any media server for post-processing or uploading the videos. It produces *compressed* videos (ogv with theora/vorbis codecs) which is then practical to send directly to Facebook as its usually just few MB.
Technically it is challenging to encode a video in AS3 and it has only become more practical to use on the computers of today or recent past, but we're trying to get around all sorts of speed issues using multithreading, domain memory, encoding in half res for web etc. On my i7 laptop the demos are working fine, i3 laptop lags behind even its so-so bearable - on desktops it should be better, didn't do extensive testing though.
AIR mobile version is not ready yet(but in progress), so for now I'd like to focus on the "web" version - basically I'd like to gather some input and possibly to hear if demos works for people (and what machine you're on etc.).
In general on slower computers and long videos I expect issues. This is more aimed towards recording around 30s of video, so ideally games with quick levels.
There are more details (more technical stuff, known isues) and 2 live demos of recording a normal game and Stage3D game, on this temporary website:
The live demos place a watermark over the finished videos.