Demographics
http://www.allied-media.com/AM/default.htm
About 7 million in US, 1 million in Canada. Annual growth rate is 6% in the US. Will double to 16 million by 2014.
From US Dept of State:
Islam is one of the fastest-growing religions in the U.S. By the year 2010, America's Muslim population is expected to surpass the Jewish population, making Islam the country's second-largest faith after Christianity.