According to the Southern Poverty Law Center, Pamela Geller is the primary figurehead of the anti-Muslim movement in the U.S. Her fame came from her opposition to the construction of a mosque and Muslim community center near the World Trade Center sites in New York. She has organized a contest to mock the image of Muhammad in a cartoon form with a $10,000 prize.
These are a couple of the websites she is affiliated with:David Horowitz is a conservative writer involved in many conservative causes, among which is an anti-Muslim advocacy. In 2008, he famously advertised to the university of of California that the Muslim Student's Association had links with the Muslim Brotherhood and Al Qaeda. He personally confirmed on his website that his organization put posters on the campus regarding this. Horowitz has a history of racist remarks.
These are a couple of websites he is affiliated with:The Religion of Peace website claims to be a "a pluralistic, non-partisan site concerned with Islam's true political and religious teachings according to its own texts." They also advocate no violence or harrasment toward Muslims, but are very inflamatory with statements such as "Don't judge the Muslims that you know by Islam and don't judge Islam by the Muslims you know," or "We see no use in pretending that Islam is just another religion - which always seems to be the assumption of those preferring not to look too closely." It's founder or staff is unknown.
This is their website: