Muslims have a right to build a mosque near Ground Zero because of religious freedoms guaranteed by the First Amendment to the United States Constitution. Non-believers are forbidden from entering Mecca because of a commandment established by God in the Qur'an. There is no hypocrisy here, unless of course something has changed about New York City and the Constitution that I don't know about. To the best of my knowledge, New York doesn't presently have a ban on Muslims and the Constitution of the United States doesn't apply to other nations like Saudi Arabia.
If it were an established law in the United States that Muslims were not allowed to practice their faith and then they still tried to build a mosque, it would be different. But as of now, Muslims enjoy the same right as those who protest against them and those who incite the nation against them in the media; all protected by the First Amendment (and somewhat by the Ninth).
You also have to remember that there are already mosques in that area and there have been for years. There was a prayer place designated for Muslims in one of the Twin Towers. For some odd reason people seem to think that because some Muslims were allegedly responsible, then Muslims have no right to that place. Muslims died there too. Muslims firefighters and EMTs were among the first responders. Muslims offered millions of dollars to help only to be arrogantly turned down by Giuliani.
To be quite honest, the real hypocrisy belongs to the people who oppose the religious freedoms of Muslims in this country, yet their own ancestors came here to escape religious persecution. The same people who oppose the building of the Ground Zero community center because of 9/11 stand on land where Native Americans were slaughtered, where African Americans were enslaved and Native Latin Americans were conquered; all legitimized by the Christians of those times. So who is the hypocrite?