I used Microsoft's address (1 Microsoft Way) somewhere in Seattle. Then I bought iTunes credit from www.ituneshop.net. There are many sites that sell these kind of prepaid credits for iTunes.
The upgrade costs more than 20USD because there are taxes as well. Read this link:
The website can help you buy credits just for the upgrade too. I bought a 50USD voucher since I wanted to buy some content too.
and so far i haven't had to pay tax.
Further review on the upgrades for IPod touch.
The applications are mainly depending on the WIFI to obtain informations for constant upgrades.
Love it. Can read and send emails in areas where there are WIFI.
Works like a GPS.
Write stuff which constantly reminding myself.
Stock and weather
Er, only reflect the area where I used for upgrade. Can change to Singapore or not?
See the icons dancing when changing locations.