try googling it, im sure you'll find something. go into an home depot, lowes, or even bed bath and beyond and ask a sales person they should know and im almost postive they're sold in all those places.
EDIT:
http://www.amazon.com/s/?ie=UTF8&keywords=led+shower+head&tag=googhydr-20&index=aps&hvadid=3249575275&ref=pd_sl_8193sxb3bi_b
http://www.google.com/products?hl=en&q=led+showerhead&um=1&ie=UTF-8&ei=65wVSp75IpSO8wTJwNzHAg&sa=X&oi=product_result_group&resnum=1&ct=title
http://shop.avon.com/shop/product.aspx?from=product.aspx&newdept=&s=frooglesearch&c=google&otc=SpaFinderAromatherapyHand-heldShowerHead&bnd=&pf_id=35986&level1_id=300&level2_id=308&pdept_id=477&ym_mid=&ym_rid=