I have put a SD 16 GB in my LG Optimus 2X P990, but it seems that the phone won't save on it. Is it possible to save/move apps to the external SD card? Or even set it to do it automatically? I have already formatted the SD card twice, and it still is not working properly.
Try App 2 SD, it should be able to move at least some of the apps.
To set it to automatic, you will need the android SDK (to use