What is this visitor cookie thing in the new 3.1 version? Could anybody explain it to me? Thanks!
I was experimenting with support for download managers at one stage and it turns out that YouTube signs every download link with a random key that's stored in a cookie (VISITOR_INFO1_LIVE). If you set this cookie to the same value in two different programs, you can copy/paste video links between the two. This option sets the value to "AAAAAAAAAAA".
I've been meaning to write up something about how it works for a while.