If you have Pro use MovieTexture
otherwise just loop through an Array of images a' la Eric like so:
and here is a very simple script from the Wiki:
answered Sep 27 '10 at 07:15 AM
I wrote a script that does just that and more. You can find it in the asset store under the name "Universal Video Texture". With my script you're not limited to just a short video clip. Works perfectly with Unity free, web, iOS and and Android.
Here's the link: http://u3d.as/content/royie-kahalany/universal-video-texture/35M