Hi! I also agree, it's a great idea to have an exhibition once we have gathered some good material for it.
Inari, your idea of comparing different locations is very appealing, I have already thought about it myself, even thought about creating a kind of comic strip with the simmilarities and differences between Mexico (where I'm from) and Australia and have written down some things like the differences in public transport for example.
I even have this very random but beautiful example:

Teddy Bears
I am going back home for a month in December, so we could maybe work out a list of people, places or activities that each of us can photograph (or draw, etc.) in our countries and in Australia and then put them all togeather to look at the contrasting points.
For example: the train in Melbourne, the metro in Mexico. Federation square and the Zocalo which is our main public square. Our neighbours, the guys at our favourite coffee shop etc.
Sunsets. Even everyday objects like garbage cans...
Or, working with the time of day like the picture you posted, say, take a picture at 10 pm from your rooftop pointing north, or something like that... Or using the Australian time to say, at 10am oz time take a picture where you are...
Well, this are some ideas, hopefully not too confusing! But I'm in!
Cheers
Cynthia.