Large white activity animator inside UIView with greyed out background displayed in middle of screen. Could be included in an asynchronous NSURLConnection web call, for instance, and on the processing of the response, it could remove itself from its superview.

gistfile1.txt

UIView *activityContainer = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
activityContainer.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:.25];
UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake((self.view.frame.size.width/2) - 40, (self.view.frame.size.height/2) - 40, 80, 80)];
indicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhiteLarge;
indicator.backgroundColor = [UIColor blackColor];
[indicator layer].cornerRadius = 8.0;
[indicator layer].masksToBounds = YES;
[indicator startAnimating];
[activityContainer addSubview:indicator];
[self.view addSubview:activityContainer];