There´s no such featrue in InDesign but you can (kind of) make it by using multistateobjects (requires CS5/CS5.5). Create a multistate object with two states, normal and large. Create an invisible button, same size with your normal image and put it on the top of your image. Set two actions to that button:
Then you have to make another button that closes your zoomed image and put it into your large statem so it appears when large state is visible and disappears when you reser normal state.
Set two actions to this button as well
Thats about it. Now you have small image and when user click it, it grows bigger. Then user close larger image by clicking close button and image resets itself to small again.
Here´s a sample:
I actually ended up to make those buttons with one action only (go to next state) and I didnt use those show/hide actions at all, i put both buttons inside states, so showing and hiding comes automatically when states are changing)