This one has been done for a while now (probably about a week), and it took very little time to build. I was hesitant to post it since I feel its missing something...not sure what though. Its based on Joe Johnston and Ralph McQuarrie's early designs for The Empire Strikes Back:
http://www.flickr.com/photos/heilemann/6113959/in/set-152728/
Anyway, onto the model:
This little guy is made from styrene, a few odds and ends, plumbing parts, and blister card plastic for the viewports in the cockpit. I started by creating the cockpit details, then built outward:
Here is the completed interior:
And here's Wedge to demonstrate how it works
And a scale shot with a 3 3/4" figure:
Now I just need to make an AT-AT to accompany it.