Watch out for the images of identical twins Sheila and Cheryl Williams. They’re poised to change the clip art world with Klip Klik Art, a CD-ROM and book set featuring more than 500 images of ethnic people from North and South America, Africa, Asia, and the Caribbean. Now the Williams’ are working to land a distribution deal with Microsoft or another Silicon Valley leader. The set of 2 CDs and 4 books took four years to make, after the twins saw a great need for more multi-cultural images in clip art.