For you Trekkies out there, just having the model is generally good enough to elicit a glow of pride; however, being able to see inside it is icing on the cake!
This 18-inch long, eight-inch tall cutaway model of Kirk's pride and joy has all of the Enterprise's secrets laid bare. From the bridge all the way to the warp nacelles, the interior is visible on the left side of the craft under a protective clear plastic outer layer. While it's not cheap at $175, that's a small price to pay for...well frankly, for something this cool!
You can find this at ThinkGeek