A couple months ago I had the pleasure of visiting the Toowoomba Flower Show in Australia.
Touring the Queens Park and Botanic Gardens I came across this beautiful specimen.
It looks very much like Dietes iridioides to me but I can't seem to find the exact variety.
This one is mainly white with only slight hints of purple. Also, as the pictures show the flower is much more dynamic with its frills compared to the common variety. It could also be Dietes grandiflora but only one website showed a picture similar to the one I saw - unlabeled with the variety though (http://wiasfotos.viawias.com/images/flowers/flowD-06-dietes%20grandiflora%20fw.jpg).
I'd like to know where I can find it to add it to my garden, as well.