In the newest version of the mod for 1.6.2, ropes don't exist anymore. They've been replaced with the Lead, an item from Vanilla Minecraft.
Ropes were created by placing five pieces of String in an X shape. It was used to lead tamed Mobs.
The Ropes cannot attach to Fences like the Leads can.
Ropes were used to pick up Kitties by their feet, though the Kitties got annoyed if you carried them this way and they would attack you once they were released.