"Boost" effect

Can anyone recommend a good way to write a shader or algorithm that would give the boost blur effect you often see in racing games like Burnout when using nitrous. (notice the blurring around the edges of the screen)
I'm also interested in a good way to do a "warp speed" like effect where stars stretch away from the camera as you fly into them.

 

This effect is often referred to as Radial Blur. Can't really recommend a ready-to-use solution, but here are a few links that should help:

Radial Blur implementation in non-Unity:
http://www.gamerendering.com/2008/12/20/radial-blur-filter/

Radial Blur implementation in Unity:
http://forum.unity3d.com/threads/radial-blur.31970/

And here are some hints how to make a racing game feel more fast:
http://blogs.msdn.com/b/shawnhar/archive/2007/09/05/vrrroom-whoosh.aspx

 

Thanks

 

I made an easy and quick boost script that works with fill amount of the nitrous meter.

Code (CSharp):

1.     using UnityEngine.UI;
2.    
3.     private float nitrousForce;
4.     public Image NitrousBar;
5.    
6.     void NitrousForce(bool n)
7.         {
8.             rb.AddForce(transform.forward * nitrousForce, ForceMode.Impulse);
9.         }
10.    
11.         void Refill(bool r)
12.         {
13.             NitrousBar.fillAmount += .1f * Time.deltaTime;
14.         }
15.         void Nitrous_Activate()
16.         {
17.             if (Input.GetButton("Fire1"))
18.             {
19.                 if (NitrousBar.fillAmount >= .1f)
20.                 {
21.                     NitrousForce(true);
22.                     nitrousForce = 50;
23.                 }
24.    
25.                 if (NitrousBar.fillAmount == 0f)
26.                 {
27.                     NitrousForce(false);
28.                     Refill(true);
29.                     nitrousForce = 0;
30.                 }
31.             }
32.    
33.             if (NitrousBar.fillAmount >= 0)
34.             {
35.                 Refill(true);
36.             }
37.    
38.             if (NitrousBar.fillAmount == 1)
39.             {
40.                 Refill(false);
41.             }
42.    
43.             if (NitrousBar.fillAmount <= 0f)
44.             {
45.                 NitrousForce(false);
46.                 Refill(true);
47.             }
48.    
49.             if(NitrousBar.fillAmount <.1f)
50.             {
51.                 nitrousForce = 0;
52.                 NitrousForce(false);
53.             }
54.    
55.             if (Input.GetButton("Fire1"))
56.             {
57.                NitrousBar.fillAmount -= 0.04f;
58.             }
59.         }
60.    
61.     private void FixedUpdate()
62.     {
63.         Nitrous_Activate();
64.     }

I hope this works for anyone trying to make a simple speed boost effect.