As requested, here is the Textured Tunnel shader effect.
Enjoy the vertigo as you gaze at the spinning tunnels that come with this shader. Head over here to see the textured tunnel effect over at http://gameswarp.com/studio/?p=333.
You can download the effect from there for free. Do remember though that you have got to do a modification to the Sprite plugin for the Textured Tunnel shader. The instructions are all explained on our web page.