[bojan]

Very interesting and simple diffraction spectroscope can be made of old CD or DVD blanks, as described on the links below:
http://astro.u-strasbg.fr/~koppen/spectro/spectroe.html
http://littleshop.physics.colostate....ctroscope.html
http://sci-toys.com/scitoys/scitoys/...ctroscope.html