Image Size - Best Practices - Mobile

In creating a mobile website, and the variety of screen sizes and resolutions, I was curious if there is a best practices to creating images. Is it better to create an image that will look great on iphone4, 960x640 and have it scaled down on earlier versions or vice versa?

What is the best approach to dealing with images and mobile devices?开发者_StackOverflow社区

I use 2 or 3 different images with correct resolution. I don´t recommend scaling because you are wasting broadband, and you could have problems with lowband phones.

if for full sized pic, scale down is a good choice if not, i thibk it doesnot matter and creat a proper one is the perfect solution