For Megacon two years ago, my friend and I decided to both dress up as different Doctors from Doctor Who. But no Doctor would ever be complete without his TARDIS. So I built a full scale replica of the TARDIS. I engineered it so it would be fully portable. I designed and built it in large sections that can quickly be put together on location. It takes about 15 minutes to assemble. Once together, it's actually quite sturdy. I built casters into the platform also so I could easily enough roll it around. Which really payed off when moving it around Megacon all day long. We entered the costume contest with it and won 1st place in the Television and Movie category. Not too bad for just two weeks worth of work.
Here's the video from the Costume contest as well: Megacon 2011 Costume Contest TARDIS - YouTube
ust let me know if anyone wants more detailed instructions on how I engineered this project.