I finally have my netbook. In the end I decided to go with the Acer Aspire One D250. The screen size is about 10.1 inch and the netbook is around 1 inch thick. The netbook comes with both Android and Windows XP OS. I messed about with Android for a bit but didn't really like it that much. However having it enabled allowed the boot-up time of the netbook to be around 15 secs which I thought was pretty cool.
But to be honest I'm in no rush to start the thing up so I decided to go with XP. I am more familir with XP and I can install more programs using this OS. Overall I am happy with the netbook and think it will be very useful whilst I am in Japan.
This is one thing that I can cross off the list. Not sure what else I need to get for the trip. But i'm sure it will come to me as the time draws nearer.