travelling is one of those unique opportunities in life where you can put material objects low on the priority list and you may find the longer you travel for , the lower they become. the key is to carry things that can be easily replaced and be prepared emotionally and financially for the possibility of losing something. because you will...
if i were you heres what i would bring:
cheap small one (nice to have one that tells the temperature or humidity, as this will always be changing. your one sounds cool but if its expensive i say leave it at home or sell it to fund the travels.
if you have a use for one then ,yes!
a cheap one, there are loads of options for remote file storage now
(do not save your passwords on it, and do not use for photo storage)....maybe you dont need to wait till you get to thailand.. they are pretty cheap anyway nowdays. and there may be insurance options if you buy it at home.
external cd drive for netbook
this will alllow you to make cds with your fotos and send them home if you want . and also to watch dvds, listen and copy cds (i think that combination is still cheaper and lighter than a laptop with built in cd drive)
1gb mp3 player
a cheap & cheerful friend for the netbook.
bring one that you will use!
this depends on your preference, but remember a big camera is not going to make local people give you a warmer smile, than a small one will. but if your big into hiking than the argument for a big camera is stronger.
i think this is a handy accesory to have, especially if money wears thin towards the end of the trip.
i would not bring
(perhaps you could have the GPS posted to you when your in Oz ..if you still want it) i dont think you will want it. but make sure it has the necessary maps installed if you decide to bring it.
(more important to have a brush that can fold up or so to keep the brush head clean)
Universal sink plug - it's very annoying having water continually run down a basin when you are trying to shave or wash.
wet toilet paper does the same thing
enjoy your travels