By the powers of WebGL, add a layer of water to your HTML elements which will ripple by cursor interaction! Maybe also by touch, though I haven't tested that.
Important: requires the WebGL extension OES_texture_float
(and OES_texture_float_linear
for a better effect). Works only with same-origin images (unless the image has the Access-Control-Allow-Origin header set appropiately).
Click here for a demo.