I really enjoy it when math reveals itself in facets of everyday life. The golden ratio, the distribution of prime numbers, and fractal patterns are all really neat concepts that can show students how math can be found everywhere you look.
Dr. Ron Eglash of Rensselaer Polytechnic Institute has developed an interesting website. His project shows a myriad of ways that math can be found in different cultural designs. My personal favourite is the way he relates grafitti art with principals of cartesian and polar geometry.
It may be too advanced for most elementary students, but secondary students may find it a good motivator to start looking at the world through a mathematical lens. The site contains tutorials and lessons, as well as information about the history of each cultural feature.
Take a look at the culturally situated design tools website, or post a link on your classroom web page to let your students investigate their own interests.