According to the Katu TV newswire, the two women - Lilli Gordon and her mother, who were on the way to the airport in Portland, Oregon, to return to California - notified Lilli's father of what had happened, and he assisted the police in tracking the handset.
"When the incident happened I was really upset and I was pretty hysterical and crying. But on the way to the airport I was like 'oh my God, if the phone is on my dad can track where it is'," Lilli told the newswire.
According to Katu.com, Lilli had just received the iPhone 4 a few days earlier, and the salesperson recommended she activate a program called Mobile Me that can track the phone through GPS.
Lilli's father was then able to bring up the phone's location on a map from his home in San Diego. He then called deputies and gave them his login information for the Mobile Me site.
A deputy in Portland then logged into Mobile Me from the computer in his patrol car and used the tracking map to find the exact location of the phone, notes the newswire.
"The deputy then met up with two Portland police officers and all three went to the phone's last location", says the newswire, adding that, after searching a car at the back of the house, they found Lilli's empty wallet and a stolen textbook.
After arresting and charging the 42-year-old suspect, the deputy accessed the Mobile Me website once again and located the iPhone nearby.
"Another deputy near the phone arrived at the intersection. Mobile Me directed him to and found three men sitting underneath a tree near the corner of North Lombard Street and North Chicago Ave. As the deputy was talking with the men, the husband sent an alert to the phone and it rang in the suspect's pocket", says the newswire.
The deputy then arrested the 45-year-old who had the stolen iPhone is his pocket, charging him with theft. The man was reportedly wanted for a parole violation.
"If we didn't have this program, this web feature, I don't think it would have ever been found," deputy Brent Laizure told the news station.
As well as proving the usefulness of the Mobile-Me service - soon to be enhanced with a new iCloud service, Infosecurity notes - the case proves anecdotal evidence that law enforcement staff in the field in the US are several years further down the technology trail in terms of mobile access to IT resources.
Most police and sheriff's departments across the US have had mobile broadband and secure laptop access to centralised resources for the last few years, whilst police in the UK are only now starting to equip their vehicles with this technology.