Tales From the Cellphone Tour

What all this means for businesses is clear, Roeding said: Companies that want to offer mobile service should be "pure-play" mobile and not try to create content, services and devices for both mobile and PC-based media. In most of the developing world, PCs and laptops are nonexistent; the mobile device is king and might remain so.

Poorer countries have typically not built extensive land-line telephone infrastructure and might never. But cell use is pervasive, meaning those countries have leapfrogged over what industrialized nations have always assumed is a necessary step in technological growth. In some countries, another leap is about to take place, as WiMax rollout begins, enabling fast mobile Web browsing.

During his trip, Roeding saw things that surprised even a mobile veteran like himself. Such as:

· In the Himalayan Kingdom of Bhutan, consumer-adoption of cellphones has followed the same arc it did in the United States: Cellphones were initially marketed for personal safety. They became a business when consumers began using them for recreational means, such as texting.

At the Tiger's Nest Buddhist monastery, at an elevation of 10,200 feet, Roeding saw a 14-year-old monk on a cell speaking to his family in another part of the country. Before he got the cellphone, the young monk said, he could never communicate with his family. But now, he said, he spends most of his time texting with other monks.

· In Nepal, ring tones are the rage. Roeding saw a group of boys squatting around a cellphone in a street. They told him they were listening to the various ring tones in the phone, the way others might listen to songs on an iPod.

Cellphones played a key role in the recent Maoist insurgency against the Hindu monarchy, allowing protesters to quickly organize. They became so effective as a tool of the opposition, the government tried to ban texting twice. During spring elections, the Maoists sent texts to voters: "A new thinking and leadership for a new Nepal . . . Give Maoists a chance this time."

· In South Africa, personal-injury lawyers have an infomercial television show that tells viewers to text the show and within 48 hours a lawyer will call. At airports, new arrivals are handed "text and win" sweepstakes sign-ups.

In some ways, Roeding found, the United States lags behind poorer countries in cellphone savvy.

"Here, we think it's cool to announce the vice president by text messaging," he said. "In other countries, there wouldn't be any other way except by newspapers."

Roeding will take his recently acquired input to his new job, which he begins in two weeks: Entrepreneur-in-residence for the Silicon Valley venture capital firm KPCB, coming up with ideas for mobile-based businesses. KPCB recently partnered with Apple to create the $100 million "iFund" to invest in new applications and products for the iPhone.