1. • Does the Ampli-Phone work with all models of the iPhone?
   

Yes, the Ampli-Phone works with all models of the iPhone.  The iPhone 3G and 3GS have a somewhat better speaker in them than the original iPhone, so these newer models will sound a bit louder through the Ampli-Phone. In the iPhone 4, the locations of the speaker and the microphone were exchanged, so the phone must be inserted into the dock with the screen facing away from mouth of the horn, or the dock can be rotated 180 degrees so that the screen faces forward again.

• Does the Ampli-Phone work on the iPod Touch?

The Ampli-Phone works only with the iPhone, iPhone 3G and iPhone 3G S.  It uses the speaker that is built into the bottom corner of the iPhone, and the iPod Touch does not have a speaker like this (the original iPod Touch and all other iPods have no speaker at all).   Also, the iPod Touch is thinner and doesn't fit the dock in the speaker.

1. • Can you use the Ampli-Phone without taking the iPhone out of its case?
   

The Ampli-Phone requires a tight seal in order to work properly, so the case would have to be removed.  There are a number of cases that have a removable portion over the dock connector, and these work conveniently with the  Ampli-Phone.