I use a mini DV recorder with 22X optical zoom.

Here is a couple edited down videos (edited down to 500some K for dial up users) I took at full zoom. Most of the animals were over 300 yards away. Except for the droptine buck he was within 100 yards. It'll give you an idea of the power of the lense.

The 22X is pretty powerful
http://www.huntingfootage.com/showphoto.php?photo=1609&cat=507

http://www.huntingfootage.com/data/507/1963Freedomslammeraug25.WMV