SAN FRANCISCO (AFP) - The majority of United States smartphone owners compulsively check handsets at least hourly, according to survey results released on Tuesday by mobile security company Lookout.

About 63 per cent of people surveyed said they check their smartphones at least once each waking hour. There were 9 per cent who said they didn't let five minutes pass without looking at their handsets.

The length of time between smartphone screen checks shrank with the ages of owners.

And while 33 per cent of people said they would be mortified if contents of their smartphones were displayed on a big screen for all to see, fewer than half protected handsets with passcodes, the survey showed.

Slightly more than a quarter of the people surveyed were unaware that visiting dubious websites or clicking on questionable links could result in devices getting infected with software viruses.

"The findings show wireless users have a striking attachment to mobile devices and a concern about the exposure of their personal information," the survey findings stated.

"While consumers recognise mobile security is an important issue, people still don't take the right precautions."

Lookout advised people to protect devices with passcodes or other locking tools and to keep devices safe in zipped pockets or closed bags when out in public.

Lookout, which provides free security software for smartphones and tablets, also advised people to be wise about which websites are visited and which applications are downloaded.

The Harris Interactive survey conducted in August was commissioned by Lookout and its partner, US telecom service provider Sprint.