Oh man! I used to build A TON of things with LEGOs. I did this back before internet was around. (Yeah, my LEGOs are that old.) I mostly built my own versions of Megazords out of them. (I was SO into Power Rangers back then.) I even did the impossible and built an 8 foot tall Megazord, complete with a custom made sword and shield. (Which was easier than you think. I had some rather special pieces that just made it easy.) However, the very moment the very last LEGO was put on to complete it, (I used EVERY LEGO I had at the time.) it all tumbled over and broke into many, many pieces.

I even mixed and matched the many different LEGO charcters that come with a number of the sets for the pilots. There were just so many ways to mix them up. (I actually did a female for the red colored zord several times. Well before Power Rangers came up with this idea themselves.)
Today, the LEGOs I hold just sit in a nice container and await the day I decide to use them again. Yet, it's been such a long time since I had some enthusiasim to build. Pretty much stopped when I discovered the joy of fanfiction.
