The OSA optics kit is now sold by Edmund Scientific: Optics Discovery Kit, OSA Optical Soc. Am. http://www.edmundoptics.com/products/displayproduct.cfm?productID=1865 FOR INEXPENSIVE LENSES, TRY: AMERICAN SCIENCE AND SURPLUS (request their mail-order catalog!) http://www.sciplus.com They sell: http://www.sciplus.com/category.cfm/subsection/21/category/188 http://www.sciplus.com/category.cfm/subsection/category.cfm/subsection/21 ALSO TRY: SURPLUS SHED OPTICS http://www.shareasale.com/r.cfm?b=98307&u=371722&m=14450&urllink=&afftrack= EDMUND SCIENTIFIC http://www.scientificsonline.com/optics.html?limit=40