Here is a little tip I picked up off an American hunting site about range finding.
All you need is two eyes , and a finger !
Put your finger (or thumb) upright at arms length.
Shut one eye and put the finger you are holding up onto your target.
Then without moving, open the other eye and shut the one that was open
Now, judge the distance that your finger has moved from the target (the distance taken is at the target),
and times it by ten.
For example, if the finger appeared to have moved 9 feet away from the target, times this by 10 = 90 feet which equals 30yds.
Simple, but it d