I have been waiting for Angry Birds Rio for a long time, but was not happy when found out can only get through Amazon app store, and since lovely At&T won't let us install anything not from the official market, we basically don't get to install this game until it comes to the market! So I did some reading and found the awesome Android Central Side Load wonder machine, see link below, the detailed instructions are on post #16
AC Sideload Wonder Machine for Windows - Page 2 - Android Forums
once you get the amazon app on your phone, you need to download the Angry Birds Rio app, it will take a while, then cannot install..... no worries, plug your phone to the PC, using mass storage mode, find the file in the folder android/data/cache/com.amazon.venezia, and copy to your PC. then use the sideload wonder machine and install the file onto your phone, and you're done!
AC Sideload Wonder Machine for Windows - Page 2 - Android Forums
once you get the amazon app on your phone, you need to download the Angry Birds Rio app, it will take a while, then cannot install..... no worries, plug your phone to the PC, using mass storage mode, find the file in the folder android/data/cache/com.amazon.venezia, and copy to your PC. then use the sideload wonder machine and install the file onto your phone, and you're done!