Keep in mind that an appraisal is only for that point in time. It will give you a general idea as to what your home is worth, but as quickly as the market is changing these days, it may not be accurate for very long. That being said, now that you have an appraised value, it might be a good idea to sit down with your insurance agent, if you have not done so in a while, to make sure you are adequately covered. With the way bay area home prices have increased over the last 10 years there are many people that are underinsured and they don't even realize it.
If you are considering selling your home, and want a more accurate value, you really need to have a realtor do a market analysis on the property. Realtors are on the ground in your community looking at houses everyday and are familiar with the nuances in your local market allowing them to be a little more accurate in determining the value of your home. Most realtors will do this for you free of charge if you ask.