Ah yes, but you can use your other phone to zoom in to find the icon on the first phone! Of course, you'll need a third phone to find the zoom icon on the second phone, and, erm, hmmm....

The nice way to invoke it would be to look for the classic "magnifying glass" gesture (ie, hold the phone against or close to what you want to look at; pull away towards you; push down again; repeat, perhaps). Could do it with an accelerometer, presumably, but I guess nearly as well by watching what the camera is doing. So, use the camera hard key to fire up the camera, then do the magnifying glass gesture and off you go. ?