I have been an outdoor enthusiast for sometime and constantly read about the outdoors as much as possible. The recent attack by a grizzly bear in Wyoming indicates there may be some serious changes going on based within the environment and bears familiarity with people. Just FYI this bear has now been killed because it poses a threat to other hunters and hikers.
A few tips might help you with a bear attack. First, bears don't normally just attack unless they are protecting food or protecting their young. In this case, the bears seemed to be very abnormal in their behavior indicating they have had previous exposure to humans and do not fear them. Likewise, their environment may be changing creating hormonal changes in themselves (i.e. contamination or territorial issues).
1. Stop and walk backwards. Show that you are not moving toward the bear or are a threat.
2. Continue talking to the bear in a calm manner to ensure that they differentiate you from other bears and animals.
3. Playing dead could also work in some situations so don't rule it out. They may push you around and test your reactions.
4. Just because a bear stands up doesn't mean it will charge. Most of the time it is a bluff. Jump, wave your hands in the air, scream, etc... to help it reassess.
5. If your with friends stand close together to look like a pack and back off slowly.
6. If you are actually attacked try and hit, bite, punch and kick the eyes and nose as soft spots.