Gnomish Gravity Well

As of current the items seems to be bugged. Although I am a gnomish engineer, I am not able to use this item; this is indicated by the text (Requires Gnomish Engineering) being outlined in red. An attempt to use the item results in the error message: "You aren't skilled enough to use that item."
As of cataclysm the quest: [The Pledge of Secrecy] (of which is offered by any Gnomish engineer, to my knowledge) was available once more. I figured that I might as well give it a shot, so I accepted the quest, filled out the paperwork then turned it it in. The Item, after completing the quest, was still not usable. So theres really no need to re-do the quest. As of the moment it seems we will simply have to wait for Blizzard to fix this items requirements, and thereby allow it's usage.
Edit: This item has been fixed as of patch 4.1

Effect: launches your character up a few yards - the distance launched may vary slightly each use. The item has no specific set cooldown, other then the global cooldown - however, you can occasionally obtain the debuff [spell=89502] which will last for 15 seconds and will prevent you from activating the item again until the debuff is removed.

Uses: This is meant to be a toy, its standard use can be for the "WTF effect" when used nearby other players. If you're a goblin however, a more practical use would be to continue to use this item until you are high enough and then use Rocket Jump to fly towards an objective location.

Another Use: Can be used to prevent fall damage (If You Are Out Of Combat!) Yes one of the limitations of the item is that it can not be used in combat and for the most part, can not be used in Instances. To prevent fall damage, simply use it prior to hitting the ground.

More Uses: Be creative, I'm sure you can find more (also I'm not going to attempt to list all of them for obvious reasons). It's one of the nice things about engineering, it allows for creativity in finding solutions.

This has so many hidden uses. For one it stops a deadly fall if you time it

I haven't bothered making it yet, and know nobody who has one, so I have to ask: can it be used while falling? Like, as you fall could you activate it to negate fall damage? Only gnomes would defy the laws of physics to create something as simple as a parachute!

Edit: I have since crafted it, and my idea is correct: you can use it as a very precisely timed, high risk parachute. Not unlike the one that you tinkered into your cloak.

As a vanity item that does nothing, is no fun to use, creates no show, and takes up a trinket slot, it is the most useless item in the game. WTB directional falling.