If you want to experience
Melbourne, the city has beautiful museums like Musuem Victoria. Sydney has also beautiful museums, for example, Hyde Park Barracks Museum. You can also go to the Arts Centre, you can see the Arts Centre Spire that is 162 m high and it's specially beautiful at night.
This is the Arts Centre Spire.
Outside Sydney there are great wild life and safaris. If it's about technology things you want to experiance you should visit Melbourne. If you want to try a special sport you should try to surf, but watch out for the sharks ;)
Restaurant recommendations:
Toko Restaurant & Bar is one of the most popular restaurants in Surry Hills. It's Japanese, modern Australian. The restaurant is romantic and takes reservations. It's most grilled food.
Address: 490 Crwon St Surry Hills, NSW

Din Tai Fung is one of the most popular restaurants in Sydney. It's Taiwanese restaurant. They have most dumplings and steamed buns.
Address: 644 George St Sydney, NSW

Rookpool Bar & Grill is modern Australian, steakhouse. They have grilled, steaked food and seafood etc.
Address: 66 Hunter St Sydney, NSW 2000

Quay is nr 1 in top 10 restaurants list of Australia and came nr 27 of 100 in worlds top 100 restaurants.
So I think they have really delicious food.

Tetsuya's is nr 3 in top 10 restaurants list of Australia and is a Japanese restaurant. Tetsuya's for the first time has dropped out of World Top 50 and is now in at rank nr 58 in 2011. But their food is really good.
Address: 529 Kent Street, Sydney 2000

Amusement park recommendations:
Luna Park is a traditional, carnival-style, amusement park. It has merry-go-round, Ferris Wheels and a spectacular Ferris Wheel etc.

Wet 'n' Wild Water World is an incredible waterpark that's open almost every year and it's only closed on the christmas day. Wet 'n' Wild Water World is the largest waterpark in the whole Australia.
