The Target saves
all of the settings required to build the project for the given processor. The best way to handle the CPU switch is to create two separate targets, one for the 908GT16 and one for the GP32. For each processor target choice, make the changes to the desired settings, such as the type of debugger used and compiler settings. You can have both targets use the same source, yet generate different object files. Now when you go to switch, you'd just pick the new target from the target drop-down menu.
---Tom