Alright, I have relatively few suggestions for minecraft, but the few that I do have seem like fairly simple fixes (I would think, but then again, I'm not a game programmer), and I like the ideas a lot. Okay, so suggestion number one. Hanging points for paintings. What do I mean by this? Say you have a painting that is 3x3 blocks. All you need to hang the painting is the middle block. If you had a painting that was two blocks tall and one block wide, you would only need the top block to hang the painting. Kind of like the actual hooks on the back of a painting. The hanging point of the painting would be determined by which block you click on to place it. Why? What is the point of this? You can jump through a painting. If you have a painting that is 3x3, you can have two blocks missing on the left side, or the right side, and it will conceal the hole, thus creating a secret passage. So whaddya guys think, huh?
Specific Haning Blocks For Paintings/Secret Passages