To add on the other answers, you can use -[NSArray reverseObjectEnumerator] in combination with the fast enumeration feature in Objective-C 2.0 (available in Leopard, iPhone):
for (id someObject in [myArray reverseObjectEnumerator])
{
// print some info
NSLog([someObject description]);
}
Source with some more info: http://cocoawithlove.com/2008/05/fast-enumeration-clarifications.html