iPhone DOWNGRADE
if you accidentally updated to the 2.0 firmware or you just rather downgrade to 1.1.4, you may use this 1.14 software solution
Here. you can read a detailed tuturial on how to downgrade your original iPhone from 2.0 to 1.14. To follow this tutorial you will need to have iLiberty (Windows, Mac), iTunes 7.5 (Windows, Mac), and the 1.1.4 firmware, as well as your favorite unlocking method.
