"The background display was definitely one of the biggest wins of our study," Consolvo said.
It's a small study, of course, but it suggested that if someone is reminded constantly of whether fitness goals are being met, it's harder to be a couch potato. It's the long-term impact that is important, Landay said.
"How do you get fit or healthy? You don't just go down to the gym today," Landay added. "It's something that happens over a long period, and it happens in many different places."
The cell phone monitors all the places where exercise occurs -- walking the dog, riding a bike to work -- not just the gym.
"Little things that could change your life also have an impact," Landay said.
Landay thinks UbiFit and UbiGreen will have a considerable impact on many lives, but he also thinks these two innovative programs are just the "tip of the iceberg."
"Right now, phones are pretty dumb. They ring when you are in meetings, because they don't know what you are doing," he said. "With simple sensing it could really know what you are doing and react the way it would if you had a decent assistant who knew you were in a meeting so don't ring."
Landay sees many other diverse applications, ranging from teaching a foreign language to improving the care of elders, "making it possible for grandma to stay in her own home instead of having to go into some kind of nursing facilities." Other sensors could interact with the phone, telling, for example, if grandma picks up a skillet, or falls down.
It's hard to learn a foreign language because few of us can learn it the easiest way, by immersing ourselves in the culture and the environment of the language. Instead, we try to learn it in a classroom.
But a really smart phone could sense that its owner is sitting in a train station, and it could behave accordingly.
The cell phone could take advantage of that situation by starting to ask questions about trains, and traveling, and the culture of Mexico -- in Spanish.
One of the neat things about cell phones is they are getting better and better at detecting exactly where we are at any given moment. Some high end cell phones already have GPS, but that doesn't always work, especially when surrounded by high rise buildings.
But cell phones have other means, including triangulation of signals from cell towers and even Wi-Fi transmitters. So even if you're lost, your cell phone will soon know where you are.
But where will it all end? Extrapolating from this inventive research, one can see cell phones equipped with mechanical noses, recognizing toxic pollutants, and maybe whether there is a strong odor of alcohol when you slip into the driver's seat. An automatic call home could save the day.
The cell phone could become the ultimate monitor of our activities, helping us achieve personal goals, warning us of nearby danger, possibly alerting others when we have done something to jeopardize our own safety.
It's not Big Brother. It's our pocket companion, and it could someday know more about us than we know ourselves.