I found the best Hay rack at Big W last week, it's a stainless steel Cutlery drainer
http://images.google.com.au/images?q...er--chrome.jpg
The pigs had no trouble getting to their hay, and it was really easy to attach to the cage. It was $5 as well, so that was an added bonus. (and I can't believe I found a picture of it on Google!)