If you use eParcel, signature on delivery is a default inclusion at no extra cost. It took us over 6 months to get this signature on delivery function working properly on our eParcel interface (which now shows "Parcel Post + Signature" on the top "Charge Code" drop-down value list), with the help of Australia Post's CEO's "Corporate Secretary" and her appointed top "Inside Sales Manager". As for insurance, they are still working on that.