In serveral projects we have used this class to load an UIImage asyncronisly with a lowres preview. It also can save the image to the caches folder so it don’t download the next time reqested. Here it is for anyone who may find it useful.
Example usage:
AsyncImageView *av = [[AsyncImageView alloc] initWithFrame:self.view.frame];
[av loadImageFromURL:@"http://goodboy.se/image.png" previewUrl:@"http://goodboy.se/image_low.png" cacheImage:NO];