That looks real good! Too bad I don't play Minecraft. Even if I wanted to, my internet connection couldn't allow it...
Just to make something clear: I will not reply to daft PMs like "Where can I find X?" or "Can you give me a link to Y?". Most of your questions are likely answerable if only you took your bloody time to look through these forums and use Google if all else fails. Sheesh...
You write "made in Minecraft Beta 1.5", but I think you mean Beta 1.4. I like the idea and it's nice that you also put some effort into creating that YouTube video. It might be entertaining to give it a try, but I'm personally unwilling to pay for Minecraft's Beta version.
I tried to make it as realistic as I could with all the traps (spikes=lava, delaying doors etc.), the only thing I could not implement was the falling floors Maybe in some new version. I admit that Minecraft is not cheap in Beta, but any hobby is like this I like making stuff in it, so I enjoy every minute spent crafting "masterpieces"