NSString *name = [NSString stringWithFormat:@"http://retroavatar.appspot.com/api?name=%d&alpha=true&fact=2", uid];
NSURL *url = [NSURL URLWithString:name];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *img = [UIImage imageWithData:data];
((UIImageView *) [self.view viewWithTag:1]).image = img;

http://retroavatar.appspot.com/

How to dwonload and use a Retro Avatar image in a iPhone App.
In this example: uid is a Facebook user id, optionally you can use any string, a name, a md5 hash of a email address and it is assumed you have an image view with tag id 1 you want to set the image for

Using the Retro Avatar API in iPhone

image

iPhone