Many people use their phone as a watch, found the survey
Camera phones could replace digital cameras as the main gadgets people use to take pictures, a study suggests.
It found that 44% of people already use their handset as their main camera.
The days of the MP3 player also look to be numbered, as 67% of those questioned said they expected their phone to replace their portable music player.
The survey, commissioned by handset maker Nokia, comes as the number of mobile phones in use around the world approaches 2.5 billion.
The Nokia research aimed to find out just how much use people make of the ever-growing list of functions crammed into modern mobile phones.
It revealed some cultural differences among those who responded, with 68% of those questioned in India being the most likely to use their phone as their main camera.
By contrast, 89% of Americans said they would stick with two separate devices. The global average of those expecting to use just one device was 42%.
Handsets look set to displace digital cameras
Tapio Hedman, one of Nokia's senior vice presidents in marketing, said handsets were starting to take over so many areas of everyday life because problems with early models had been ironed out.
"There's a threshold a gadget must reach for it to be accepted as a multi-function device," said Mr Hedman.
"If picture quality is not good enough and browsing is a pain, then it will not be accepted."
Too great a loss
The research found that, on average, a third of people regularly browse the net on their phone.
At the same time it revealed that for many, mobiles are taking over from more mundane devices.
For instance, 72% of those questioned in the survey use their phone as their alarm clock, and 73% use it instead of a wristwatch.
Mr Hedman said the importance of people's mobile phones was shown by the fact that 33% would rather lose their wallet or purse than misplace their mobile.
And a fifth of respondents would rather lose their wedding ring than their handset.
The Nokia research into mobile habits questioned 5,500 people aged between 18 and 35 in 11 nations in early 2006.