The rope was created for all those times you wanted to rappel down a large cliff or cave. The rope must be attached to a solid block above where you place it.
Any rope blocks placed directly next to other rope blocks will be added to the bottom of the rope. Destroying a rope piece will decrease one from its length. Destroying the block the rope is anchored to makes the entire rope break.
The recipe is shown in the video.
If you’re having problems please reinstall ModLoader. Then make sure you deleted META-INF from minecraft.jar. If that doesn’t work, and you’re sure you reinstalled modloader just now, it could be a blockID or itemID conflict. These mods will automatically create a file in (minecraft folder)/mods/DJoslin/, open that file and change the ID to an unused one.
For Minecraft 1.5.2
For Minecraft 1.5.1