Some sample code for a horizontal paged UIScrollView with a gap between each image, like Photos.app (which looks nicer when paging).

gistfile1.mm

/*
	Some sample code for a horizontal paged UIScrollView with a gap between each image (which looks nicer). Note - not using contentInset, we want each page to fill the iPhone screen and the gap only to be visible when scrolling (like Photos.app).
	
	Taking the iPhone status bar into account - our viewport is 320x460
	Our UIScrollView is therefore set in Interface Builder to 340x460 with a -10 X offset (so it's larger than the viewport but still centred)
	
	Then we do the following...
*/

// Our image filenames
NSArray *imgNames = [[NSArray alloc] initWithObjects:@"0.jpg", @"1.jpg", @"2.gif", @"3.jpg", @"4.jpg", @"5.png", @"6.jpg", @"7.jpg", @"8.jpg", @"9.png", @"10.jpg", nil];

// Setup the array of UIImageViews
imgArray = [[NSMutableArray alloc] init];
UIImageView *tempImageView;
for(NSString *name in imgNames) {
	tempImageView = [[UIImageView alloc] init];
	tempImageView.contentMode = UIViewContentModeScaleAspectFit;
	tempImageView.image = [UIImage imageNamed:name];
	[imgArray addObject:tempImageView];
	[tempImageView release];		
}

CGSize pageSize = scrollView.frame.size; // scrollView is an IBOutlet for our UIScrollView
NSUInteger page = 0;
for(UIView *view in imgArray) {
	[scrollView addSubview:view];
	
	// This is the important line
	view.frame = CGRectMake(pageSize.width * page++ + 10, 0, pageSize.width - 20, pageSize.height);
	// We're making use of the scrollView's frame size (pageSize) so we need to;
	// +10 to left offset of image pos (1/2 the gap)
	// -20 for UIImageView's width (to leave 10 gap at left and right)
}

scrollView.contentSize = CGSizeMake(pageSize.width * [imgArray count], pageSize.height);