Advice on using vector graphics on the iPhone

A question for the seasoned iPhone developers, what is your preference for graphics in an iPhone app? I have turned to PNGs because I read that is the preferred image format and they are the most efficient format for the OS in terms of performance. However I had read you should try to use svg graphics so they s开发者_运维问答cale up on the iPad. I started reading up on svg for my next app and thought the format was natively supported by UIImageView, but it seems you can only render them in UIWebviews or programatically. My belief was a lot of the latest graphically-rich apps used svg graphics, is that an incorrect assumption?

Thanks for any advice/comments.

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I think using SVG graphics would cause a ton of problems and I'm not aware of any apps that use it. It's probably a much better idea to use PNGs and just have different sizes for iPhone, iPhone 4 and iPad.