images for slideshow

does anyone know of some really good sites or places to get some crazy good renderings, sketches, drawing samples…my highschool art teacher wants me to give a quick slideshow on industrial design…and would be cool if the pics could show really good photoshop work, the class does a lot with that program and it would be nice if i could show these kids some amazing pics…i have some stuff of my own, but the more the better, thanks.