how can I put a clickable link in my video?

How can I put a clickable link in my video? I saw it in a youtube video by Mark - http://www.youtube.com/watch?v=w6brdwY-dvU&feature=related. There is one for subscription and one for clicking thru to the site.

Does this take special software? Is it a feature of youtube?

Thanks,
Greg

It's easily done with annotation inserts. More info on Annotations can be found here:

http://www.youtube.com/watch?v=XAG3z4scWTw&feature=channel_page

Thanks for the reply Dave. What a nice feature. Any way to do it outside of YouTube?

Unfortunately youtube is limiting it to link to youtube sources only for security reasons. I don't know of any programs or other ways to embed links onto the flash player.