If you wanted to spend $1000 then the galaxy Tab, would be the best solution.
Much better than an iPad, as it can actually do voice calls, has usb, bluetooth, and much more, including being able to view flash websites, something that an iPad can not do.
Is also smaller, and much more portable than an iPad.
If not, than test drive either of the new tabs from telstra, and or optus, for around $300
One of the problems with having a TAB, is you need to have a 3G connection to use it when away from your normal WIFI at home, and with the price of 3G data, it is best to go on a plan.
Which opens up another option for those that already use 3G for their home internet, which would be to get a Galaxy Tab on a plan and pay nothing up front for it, and turn it into a WIFI hotspot at home, for your home internet connection