A lot of time passed from his return to the creation of his Twitter account, so here's a summary of what happened in between—
Tiger struggled all year with his golf swing, and he split with Hank Haney, choosing Sean Foley as his new swing coach.
Even this move was a small PR victory. His third professional swing instructor since joining the PGA Tour, Foley, unlike Harmon and Haney, had other students.
Woods was no longer the "chosen one," entitled to whatever teacher he pleased. Instead, Woods placed himself on the same level as his opponents.
On to Twitter, however. On November 17, Tiger joined the Tweeting world, saying "What’s up everyone. Finally decided to try out twitter!" While this move may seem a little odd for Woods, this move sums up Tiger's theme of the year—change.
Never, never, would the "old" Tiger Woods let you in on his everyday activities, until now. The joining of Twitter made Tiger a more likeable person. Any person could click follow, and bam, you now have some insight into Tiger Woods' life. For example, here's the picture he posted of himself working on his video game: http://yfrog.com/gz01x7j
Something like this is exactly what people want. They want to know Tiger is human and has a life outside of playing in golf tournaments and practicing golf for a rumored eight hours a day.