Tiger's Ball Up a Tree
First, if Tiger could not find and identify a ball as his within five minutes, he would be required to play a ball from where he last played under penalty of one stroke; commonly referred to as stroke and distance (Rule 27-1c).
Second, if he did spot a ball in the tree, he would be required to identify the ball as his. If you’ve played golf in Florida, you know that those palm trees can harbor a lot of golf balls gone astray. If he was able to positively identify a ball as his, he would be able to invoke the unplayable ball Rule and save himself the distance portion of the penalty.
Lastly, if he was not able to physically climb the tree to retrieve the ball, he would be able to use any means available to him to identify a ball as his including the use of binoculars or high power camera lenses (Decision 27/14).
In two different places in the Rules of Golf, a strong recommendation appears to put an identifying mark on your ball: Rules 6-5 and 12-2. That recommendation exists for exactly this purpose. Tiger’s unique combination of identification marks on his ball are the word “Tiger” is imprinted on his golf balls by Nike and he adds a line to assist him in lining up his putts (Decision 20-3a/2).
Tiger, with the assistance of the PGA Tour Rules staff and some binoculars, was able to positively identify a ball in the tree as his. As a result, he was able to invoke the Unplayable Ball Rule (Rule 28). Since the ball was still up in the tree, the reference point for him would be a spot directly underneath the spot where the ball lay (vertical distance being ignored). He was then able to drop a new ball within two club-lengths of that spot using the third option of that Rule.
Later, after Tiger left the area, a spectator actually shimmied up the palm tree and retrieved a nice souvenir of a Nike golf ball with the word “Tiger” imprinted on it with a line drawn on it as well.
Remember, use the index or the table of contents to find the correct Rule that applies to the situation and follow the Rules of Golf to help yourself to enjoy the game of golf.