The challenge is as follows: -
Successfully find any cache (not owned by you, or previously visited, or told where it is, or THIS cache) within 12 seconds of you first getting within 20 feet or 6 metres of the cache, as shown on your GPSr. If successful, you should include the time it took you to find the cache in your find log for that cache, in the following suggested format : -
12 Seconds of Caching (GC2BR3R) – I found this cache in xx seconds 
Having achieved the task you are then free to visit this cache at the publish co-ordinates, whereupon please take a *photo of you performing a gurn (if you are unsure of what a gurn is, please see an example at the bottom of this page and on my profile page). This photo maybe be uploaded with your log and your log should include a reference to the cache you found within 12 seconds.
i.e.
I found 'A feet of marvellous engine earring (GCxxxx) in 6 seconds.
Why 12 Seconds?
I was inspired by the cache ’12 Days of Caching ( GC1K1TK)’ - Although a rather unpleasant and painful verruca prevents me from undertaking such a committed challenge at present.
And
The first successful flight of the Wright Flyer, by the Wright brothers. The machine travelled 120 ft (36.6 m) in 12 seconds at 10:35 a.m. at Kitty Hawk, North Carolina. Orville Wright was at the controls of the machine, lying prone on the lower wing with his hips in the cradle which operated the wing-warping mechanism. Wilbur Wright ran alongside gurning all the way to balance the machine, and just released his hold on the forward upright of the right wing in the photo (See Background photo). The starting rail, the wing-rest, a coil box, and other items needed for flight preparation are visible behind the machine. This was considered "the first sustained and controlled heavier-than-air, powered flight" by the Fédération Aéronautique Internationale.
*On the lighter side: Whilst I realise that I cannot insist on any additional logging requirements (i.e. upload a photograph of you gurning at the cache location), I respectfully ask that you seriously consider uploading one in the name of fun and in the spirit intended. – Thank you.
P.S. gurning pets do not qualify!
This is the picture I took while placing the cache.
Once you have successfully found a cache within 12 seconds, found and logged this cache and uploaded your photo, you have earned the privilege to display this medal on your caching profile. Copy and paste the following :
<a href="http://www.geocaching.com/seek/cache_details.aspx?wp=GC2BR3R"><img src="http://img.geocaching.com/cache/e5755c58-9fd0-4623-bee7-0663f2edf445.jpg"></a>
