Bismillah = "In the name of Allah" = 666
On the Zola Levitt program, Walid Shoebat, a former PLO terrorist now Christian evangelist, said that when he first saw the Greek symbol that is translated in the Bible as 666, he immediately read it as the Arabic character “Bismillah” (some spell Bismilla) which means "in the name of Allah." If you have Real Player simply click here. You can scroll the Real Player to the 12 minute mark where the interview with Walid Shoebat begins. Otherwise visit http://www.levitt.tv/ and scroll down to section "Age of Terror", and then "Mark of the Beast", to view the interview.
Below (left) are photos of Greek symbols translated in the Bible as 666, from Free Jesus.net: The gold symbol (bottom and right) is Arabic for "Allah" or "in the name of Allah" when turned and mirrored. Additionally, crossed swords are a symbol for Islam. So in 666 we may find symbols for both "Islam" and "in the name of Allah".
If Shoebat's account seems a stretch, even though Arabic was his first language and Islam the religion he was indoctrinated into, consider how this Arabic character is stylized into many different artistic forms. Consider also how some look for this character in trees, clouds and such, as this search link attests - even in a fish!
Source: http://www.beholdthebeast.com/islam__quran_and_666.htm