They are pretty much essential, but you may want to ditch your mobile phone for ever after reading this.
The average handset carries 18 times more potentially harmful germs than a flush handle in a men's toilet, tests have revealed.
An analysis of handsets found almost a quarter were so dirty that they had up to ten times an acceptable level of TVC bacteria.
One of the phones in the test had such high levels of bacteria it could have given its owner a serious stomach upset.
While TVC is not immediately harmful, elevated levels indicate poor personal hygiene and act as a breeding ground for other bugs.
The findings from a sample of 30 phones by Which? magazine suggest 14.7million of the 63million mobiles in use in the UK today could be potential health hazards.
Hygiene expert Jim Francis, who carried out the tests, said: 'The levels of potentially harmful bacteria on one mobile were off the scale. That phone needs sterilising.'
The most unhygienic phone had more than ten times the acceptable level of TVC and seven were above the threshold.
This worst handset also had 39 times the safe level of enterobacteria, a group of bacteria that live in the lower intestines of humans and animals and include bugs such as Salmonella.
It boasted 170 times the acceptable level of faecal coliforms, which are associated with human waste.
Other bacteria including food poisoning bugs e.coli and staphylococcus aureus were found on the phones but at safe levels.
Which? researcher Ceri Stanaway said: 'Most phones didn't have any immediately harmful bacteria that would make you sick straight away but they were grubbier than they could be.
'The bugs can end up on your hands which is a breeding ground and be passed back to your phone. They can be transferred back and forth and eventually you could catch something nasty.
'What this shows is how easy it is to come into contact with bacteria. People see toilet flushes as being something dirty to touch but they have less bacteria than phones.
'People need to be mindful of that by observing good hygiene themselves and among others who they pass the phone to when looking at photos, for example.'
Which? has previously found that some computer keyboards carry more harmful bacteria than a lavatory seat.
3 Months Protection with Just One Wipe
Take advantage of our 25% Off Summer Sale