Reading one row of pixels from camera

Other Hardware Sensors
2

Parallax sells a 1-D line scanner that you might check out. Arduino
should be able to process its data easily [I think].

http://www.parallax.com/Products/Sensors/tabid/86/Default.aspx

http://www.parallax.com/Store/Sensors/ColorLight/tabid/175/CategoryID/50/List/0/SortField/0/Level/a/ProductID/566/Default.aspx