FYI:
http://www.snopes.com/politics/gasoline/gasout.asp (this has been circulating since 2001)
"A boycott of a couple of brands of gasoline won't result in lower overall prices. Prices at all the non-boycotted outlets would rise due to the temporarily limited supply and increased demand, making the original prices look cheap by comparison. The shunned outlets could then make a killing by offering gasoline at its "normal" (i.e., pre-boycott) price or by selling off their output to the non-boycotted companies, who will need the extra supply to meet demand. The only person who really gets hurt in this proposed scheme is the service station operator, who has almost no control over the price of gasoline."
so what we need to is circulate that rumor, and buy from the stations being boycotted.
and the other popular circulated boycott:
http://www.snopes.com/politics/gasoline/nogas.asp (circulated since 2000)