How to Create a Universally Unique Identifier (UUID)

- (NSString *)CreateUUID
{
    CFUUIDRef uuidRef = CFUUIDCreate(NULL);
    CFStringRef uuidStringRef = CFUUIDCreateString(NULL, uuidRef);
    CFRelease(uuidRef);
    NSString *uuid = [NSString stringWithString:(NSString *)uuidStringRef];
    CFRelease(uuidStringRef);
    return uuid;
}