I was in a group where we had to make a 3D model for the transfer situation at Broadway-Lafayette station.  Instead of using CAD or some other "static" program, we used Duke Nukem 3D!

Once the people at the Metropolitan Transit Authority saw it, they got us to make a better version.  This time we used QUAKE II!  We used a very nice (and free) editor called BSP .

Here are some screenshots (I hope to put more of them up):