what is the best way to fight for justice?

Slap on some blue spandex and throw on a red cape!

Or you can get involved with your local government and see how you can volunteer. Just a little bit of help can make a difference :)

Vote! And in extreme situations of injustice, peaceful civil disobediance (Think Martin Luther King Jr.)

Become politically involved...if you don't have the power to change things you'll just get frustrated...kick your party in the butt until they shape up to where you want them to be and do your best to eradicate the opposition...

Get a clue from the Islamics

Grass roots, activism, picket line, etc... Keep it peaceful or you will defeat the whole cause in the eyes of others.