Floocraft

Floocraft brings the quaint teleportation system from the world of Harry Potter into Minecraft. Simply craft some Floo Powder, throw it into a lit fireplace and choose your destination. Fireplaces can be almost any size or shape, can be made of most solid blocks including blocks from other mods, and can even have redstone incorporated into them.

Other features include:

• Floo Torches, which can teleport you to a nearby empty space, or a nearby Floo Torch if there is one
• The Floower Pot, a container for your powder that can also convert nearby fires to Floo fires automatically
• If enabled, villagers, mobs and items can teleport to random fireplaces when they walk into a Floo fire
• The ability to "peek" into certain fireplaces without teleporting there

This intro video, the original booster of Floocraft's popularity, is provided by TheDiamondMinecart. Please note that it uses an older version with fewer features.