yeah, thats what I do!!!

Tubepopper takes youtube videos one step further. All you need is a little creativity. You can add speech bubbles to these videos and showcase your creativity to the world.
Go ahead, make fun of that video on youtube the way you always wanted to.

In their own words :
You can use Tubepopper for:
– Making cartoons out of Youtube videos (Make people think funny things, when they are saying something different)
– Subtitling a video to make a new story out of the images
– Translating existing video into new languages
– Commenting on a video
Here’s a tubepopper video made by the guys behind this site:
Kiran
October 24th, 2008 at 5:39 pm
I sent you an email. Need help again.
Now the same feature as above is also in Youtube in Annotations.
Check my videos. I have added annotations
http://www.youtube.com/watch?v=lALtlwsFpaw
http://www.youtube.com/watch?v=hsEsiTwWeZU
Nischal Shetty
October 24th, 2008 at 6:07 pm
@Kiran
Check your mail. Checked out the videos.. Thanks, I did not know about annotations