This one's done very well. Not as funny but very well edited.
http://www.campchaos.com/show.php?iID=646
I've seen this one a while back. Still not bad.
http://www.campchaos.com/show.php?iID=645
and a non bush one: Imagine how hard it is for those 2 anchor people to keep a straight face. ahh.
http://www.campchaos.com/show.php?iID=855
that website had a few really good ones. Most have been distributed widely on the net though.