TSC is exactly right. The price of gasoline is controlled mainly by supply and demand. This idea of a boycott has been around for awhile, and it just won't work. You don't need any links or charts, just use your head.
If 10 people buy 10 gallons from 10 stations, thats 100 gallons used. If these 10 people decide to boycott 5 stations but don't lower their usage, you'll end up with the same 100 gallons used,but from 5 stations instead of 10.
Why would the remaining 5 stations lower their price ? their demand has doubled. If their demand has doubled, where do you think they're going to get that extra gas ? They're going to buy it from the ones that were boycotted.
As was stated earlier in this thread, the only way to decrease the price of gas is through less demand or greater supply.