Here's the gist. You can craft one ender pearl into two ender dust. Ender dust has three uses I've thought of yet. Potions, Crystals, and Plates.
You can add ender dust to a potion to make it compatible with other potions. You can mix together two compatible potions to create a potion with both their effects. Note that the tiers and durations of these effects are reduced. So while having each individual potion might be more effective, a multi use potion might be more practical, particularly while mining, since you want to have your inventory open. I, for instance, always carry a speed potion, a regeneration potion, and a third potion depending on the activity, usually a fire resistance potion. I rarely ever use more than one of these before being able to restock, so I would carry a multi use potion with me instead. But if I'm taking a long journey to get to new lands, I'd use regular speed potions.
You can craft a lava bucket with six ender dust and two sugar to craft an ender crystal (you get the bucket back). You can place an ender crystal as a block, and when you use an ender pearl, if the pearl lands within a sixteen block radius of that crystal and the crystal is visible from that location (to prevent on servers hiding an ender crystal underground to trap and kill players) you will be teleported onto the crystal. The crystal also has a 50% chance of nullifying the damage caused by teleporting. This allows a sort of "ender rail line" where you throw ender pearls and the crystals correct your course.
Ender plates are crafted by surrounding a stone pressure plate with ender dust. Stepping on an ender plate will teleport you to a random block within a sixteen block diameter horizontally, and up to three blocks vertically. By removing all other teleportable blocks in that area, this can also be used as reliable fast transport. It could be used to remove mobs from your area, or to provide an emergency exit to your home. Or maybe you just want to have some fun.
These are really just throwaway ideas, so I don't expect them to be too good, but what do you good people think?