Islamic Patterns
Pattern in Islamic Art
Archive of Islamic Patterns by Region
Teachers' resource: Maths and Islamic art & design
Geometric Patterns in Islamic Art
Wikipedia: Islamic geometric patterns
Islamic Art and Geometric Design: Activities for Learning
Maths takes Shape - Islamic Patterns
The 'Maths takes Shape' website has excellent instructions on how to create tiles that can be used to make Islamic patterns.
The other websites are useful for background information and to provide ideas.
Scratch Files
Reflected Patterns
(Magic Carpet Designer - MCD Reflect
Rotated Patterns
(Magic Carpet Designer - MCD Rotate