Dummy phones are quite usel- no, I take that back. They're marvelous tools to see how a device would fit in your hand and to see if the form factor is right for you. That said, they're still quite useless (most retail locations for most carriers offer you the chance to play with an actual unit anyway). It doesn't keep us from getting excited that dummy units are out for the Motorola Charm headed for T-Mobile. Even though all signs are pointing toward the late-August delay being true, several retailers have gotten their dummies in ready to be flaunted in front of paying customers.
You might want to see if you can find one of these sitting inside of a T-Mobile store if you fear the device might be just a bit too small for your liking.