Modloader. Everything updated for 1.6.2.
The mods directory will now be located in the same directory as minecraft jar, unless the default game directory is changed, where it will act like it had on older versions. Read this entire post. All of it. Downloading the mods means you agree to the disclaimer. SinglePlayerCommands. TooManyItems. Marglyph's TooManyItems Create and enchant items in-game, including mod items.
Save and load entire inventories. Create unlimited stacks and tools.