Minecraft Over-Engineering: http://www.youtube.com/playlist?list=PL9A567A818D5F6ED3
*edit* If you want to be able to control the door from both sides, make design 2 and then make the modifications seen in this image: http://i49.tinypic.com/242j2vd.png
In the comments of the Over-Engineering Ep1 video, people have been requesting that I make a tutorial for a 3x3 sand door, so here's two!
Donate: http://bit.ly/St3venAU_Donate
Texture Pack: Faithful 32x32 (http://goo.gl/FFfaS)
Music: 'Cipher' by Kevin MacLeod. Available at http://incompetech.com/m/c/royalty-free/index.html?keywords=Cipher under a Creative Commons Attribution 3.0 Licence (Free to use commercially with attribution: http://incompetech.com/m/c/royalty-free/licenses/)