The art of politely gathering food from other hikers/campers by means of conversation without actually asking for it. If one asks for the food it is no longer yogi-ing, but rather it is simply begging, which is shameful. A term heard on the AT and is a common act to find, if one pays attention.
"They have frosted Pop-Tarts! Let's see if we can Yogi some off of them."...yogi-ing