By following these upgrade instructions, you can bring your Nokia N80 up to full N80 Internet Edition status (commonly known as Nokia N80i/N80ie).
This irons out many bugs and gives your phone a whole host of new features, including the ability to run Truphone.
Note that this process may not work on all Nokia N80 handsets and that you undertake this exercise at your own risk. Truphone implies no warranty by providing these instructions. The process only uses official Nokia software but please be sure to read all the instructions and terms and conditions carefully.
STEP 1.
How to upgrade your Nokia N80 to N80 Internet Edition
STEP 2.
How to install Truphone on your Nokia N80 Internet Edition