On: Abū Rayhān Bīrūnī -- Medieval Islamic Scientist, quite a read...

[sharjeel]

<i> I can't think of any famous Arab scholars from the period (not an expert though - let me know if there are any) </i>

Take a look at the creator of cryptanalyis:

http://en.wikipedia.org/wiki/Al-Kindi

He was an arab philosopher, scientist, astrologer, astronomer, cosmologist, chemist, logician, mathematician, musician, physician ...