1. [UIImage imageNamed:]

This retrieves an image from the ‘main bundle’ and loads it.

Try this:

• [UIImage imageNamed:@"foo"]

On iOS 3.1.3, 3.2. this doesn’t seem to work
On iOS 4.0, or later, seems to work for .png files, but not for .jpg files.

Instead, use this:

• [UIImage imageNamed:@"foo.png"]

This will work on all iPhoneOS/iOS versions and will also retrieve ‘@2x’ variants of your pics when available.

2. [UIImage imageWithContentsOfFile:]

Avoid using this. This won’t reliably retrieve ‘@2x’ variants (high quality images for retina display devices).