The Stone Age soon introduces itself in the form of Dani men who silently offer stone adzes and necklaces of petrified toadstools for $10 each. Half that amount of money buys your very own koteka, or penis gourd, teased to its maximum length by skilled gardeners. The men may use the proceeds to buy cowrie shells, still the currency of choice in remote villages, which are then used to buy pigs, which in turn are used to buy wives.

The 20th century economy also thrives, as you find when the Dani stop to pose for photographs all over the valley. The click of the camera shutter is followed by a silent demand for $1--the index finger pointed at the sky at arm's length. At Akima village, the keeper of the tarred mummy of the warrior chieftain Werapak Elosarek hoots a war cry to back up a demand for a $3 snapshot fee.

Tourists keep the Dani equally entertained. Five men in the village of Kurima burst into peals of laughter at the sight of our sweat-soaked clothes after half a day's hike. For another laugh, they watched us try to stay clean while crawling into their mushroom-shaped hut, where we were invited to spend the night with them and their pigs. When we asked for directions to the next village, they guffawed again and took turns bragging about how fast they could walk the distance.

Two little girls led us for an hour across a plain of meter-high grass on their way home from school near the village of Jiwika. Wearing the soiled dresses that missionaries consider dignified, they guided us around pits and streams as we took in a view of limestone crags and rare birds. When we reached the road, the subtle entrepreneurs each raised the $1 index finger.

To get this close to the Dani, you don't have to rough it or go over budget. The perfect base for day trips is Wamena, where the 20-room Baliem Palace Hotel offers double rooms with a hot shower and satellite television for $40 and Chinese restaurants serve meals for less than $10. Pugima, the nearest village, is an easy two-hour walk out of town.

It wouldn't be an adventure without getting stranded at least once. Down at the Tangma airstrip, where the cliff we had just descended looked too vertiginous to climb, a Dani schoolteacher delivered some bad news: flights had been canceled for a week. We would have to walk back to Wamena in the morning. He invited us to join in Dani songs with his "cousins" around a campfire in his clapboard bungalow, which was furnished like a Dani hut, and offered us an authentic Dani feast--a baked sweet potato, a warm strawberry Fanta, a bowl of instant noodles flavored with monosodium glutamate, and a hard-boiled egg. It wasn't until we fell asleep that the fleas began to bite.