This ones simple. If you have an existing ANZ online saver account and are currently getting 4.5% interest. Then call them and say - "I am planning to move my savings to ING direct to get there 6% rate - but if I could take advantage of your 5.75% introductory rate I would stay."
Basically a 30s phone call gets you a higher rate of interest without the hassle of opening an account or moving money.
another fine example of honouring company disloyalty… where they should reward loyal customers by giving them the interest without having to call up.