There's a few threads devoted to posting pics and videos of people's games. Why not post a zipped copy of their World files instead? Then everyone could have a run around and take a proper look at what they've built.
I guess they'd have to list what version and what mods they were running so that other people could make sure that they've loaded the same ones, or the "saved game" would probably crash.
I had a look at mine, they're around 16 Mb in size, but mine are relatively new and not very extravagant, I imagine some could be a lot bigger. But then what size are the video files people are posting? Food for thought.
Cheers,
Andrew.