Piston

Pistons are blocks capable of pushing adjacent blocks, depending on the direction they face. The original version of this feature was a mod posted on the Minecraft Forums by Hippoplatimus. Pistons will be added in a later version. Pistons will be slightly altered from the original version, and the usage section below only explains the mod's usage. Pistons are currently delayed since jens has switched projects, But rumors are that they will be added to Beta 1.6. Jeb said he would not get them to 1.5 but that he would get them soon

Usage
The original piston mod is capable of moving up to 16 adjacent blocks (except obsidian, bedrock and other Pistons), depending on the direction the piston is oriented. To change the orientation, a user would only have to right click on it, and the piston would face them.

When Gravel, Sand and active TNT are placed on a piston facing upward, they will launch into the air, then fall back down into place. Other things that can be launched are entities and items. If the player is in front of a piston facing sideways, the player will be shoved about 3 blocks away from the piston. If the player stands on the blocks that the piston is pushing, the player will fall through the blocks.

Pistons are controlled using redstone currents.

Crafting
This is the recipe from the mod, but Jeb might change it when it is added.

Trivia

 * When the mod is installed, its dec. ID is 100.
 * The unusable piston head can only be obtained by hacking or using an inventory editor, and its dec. ID is 101.