[NSKeyedArchiver archiveRootObject:rootObject toFile:path];

NSString *error = nil;
NSData *mySerializedObject = [NSKeyedArchiver archivedDataWithRootObject:myObject];
NSData *xmlData = [NSPropertyListSerialization dataFromPropertyList:mySerializedObject
						format:NSPropertyListXMLFormat_v1_0
						errorDescription:&error]:
if( xmlData ) {
	[xmlData writeToFile:myPath atomically:YES];
} else {
	NSLog(error);
	[error release];
}