gistfile1.m

    NSMutableData *data = [NSMutableData data];
    NSKeyedArchiver *archiver = [[[NSKeyedArchiver alloc] initForWritingWithMutableData:data] autorelease];
    [archiver setOutputFormat:kCFPropertyListXMLFormat_v1_0];
    [archiver encodeObject:self.attributedString];

// Sanity check
    
    NSMutableDictionary *dict = [NSPropertyListSerialization propertyListFromData:data                               
                                                                 mutabilityOption:NSPropertyListMutableContainersAndLeaves 
                                                                           format:nil 
                                                                 errorDescription:nil];