Last month Google announced the addition of automatic captioning to YouTube videos.

The captions are generated by machine translation, so don't expect perfection. Based on the automatically captioned videos I've seen so far, it may be too much to expect comprehension.

Spoken English generally runs at about 120 words per minute, so it's not surprising that even human-captioned live events are often marred by mistakes. Machine translation from speech to text is still a developing art, but it's coming along well enough to make this worth trying.

Google posted an announcement to their blog about this feature here:

http://googleblog.blogspot.com/2009/11/automatic-captions-in-youtube.html

And their help files provide instructions on how to use autocaps, as they call them, and autotiming to transform a simple transcript to captions:

http://www.google.com/support/youtube/bin/answer.py?answer=100077

So now there are tools in place to help make captioning videos easy and widespread. If you videoblog and play with this, let me know how it well it works for you.