My miniature hommade Amateur Radio Transceiver. A hiker named SloGoin designed it and I built it. It weighs about 2 oz and fits into a little altoids tin. I was able to lay in my sleeping bag with my morse code key in my hand and earbuds in my ears and communicate with friends all around the United States while the other hikers bunked right next to me heard nothing at all and thought I was sleeping. This rig also won me the top prize in the Hommade Gear Contest at Damascus Trail Days 2005.
AT hiker 2005
trail name MacGyver
my alias: Beartrack