If it's a reasonably nice restaurant I think having the phone ring or answering it and having conversations is the height of bad manners. After all people go to cafes/restaurants to relax. When mobile phones first hit the scene, the standard etiquette was (and I think it still is) to switch of the phone or put it on silent at worse - and if you HAVE to answer the call - go outside the restaurant to speak.
When I'm on a one on one dinner I would lose all respect for the person answering their phone at the table - unless someone was gravely ill and I was informed first.
In an internet cafe/hotwired cafe a la Freo, I'd understand if people were skypeing. I do think it's sad when everyone on a train is playing games, texting or phone conversing - takes all the joy of communication even if it's just looking at people. Certainly, I'd get cheesed off in a cinema or the ballet or a funeral or wedding and someone's phone went off.
Mind your mobile Manners
The Australian Mobile Telecommunications Association (AMTA) encourages individuals to use their mobile phones in a responsible manner and to be considerate and aware of situations where using their mobile phone might annoy others.
The mobiles industry wants as many people as possible to enjoy the benefits of mobile telecommunications. There are more than 24 million mobile phone subscribers in Australia, so please remember to follow these simple courtesies.
When in doubt, always go out: When possible go outside or to another room to make your call if your call might disturb others. Also, features such as text messaging answering services, call diversion and vibration alert can be used to receive important calls without disturbing others.
If you can’t turn it off, use silent mode: If you need to keep your phone on for important calls, then turn it to silent or vibrate mode. It’s the ring of a mobile phone in inappropriate places and times such as at the tennis or in restaurants which annoys people the most.
When required turn your phone off and check it’s off: There are some places where people should never talk on a mobile phone or send text messages and where the ringing of a mobile phone or message alert is considered highly unacceptable, such as: movies, stage shows, weddings, funerals, concerts, speeches, classrooms and lectures. In these cases, turn your phone off and remember to check it’s off before you enter the venue. You can always check your voicemail, text messages or your answering service afterwards.
Keep your conversations private: People’s sense of personal space varies in each situation. Making a call in a busy pub may be okay, but talking loudly in a confined space like a lift or on a train tends to infringe on others personal space. Be aware of where you are and who you are with and what others are doing before deciding to make or accept a call. In some situations it might be better to send a text message.
Speak softly: Mobile phones have very sensitive microphones that can pick even the softest voice, so there is no need to shout. If you are having trouble hearing the other caller, check that you have the volume on your phone set high enough.
You don’t always have to answer- use your messaging service: It’s a natural reflex to answer your phone if it rings, however, if you forget to put your phone on silent or vibrate mode and it rings at an inappropriate moment, send the call to voice mail or your answering service (usually by pressing the hang-up key).
Talk to the one you’re with: If you receive a call during a conversation, send the call to your voicemail or answering service. Your first priority should be to the person you are with. However, if you are expecting an important call let the person you’re with know before the call arrives and excuse yourself before accepting the call.
Don’t send inappropriate messages: Messaging is a great way to communicate, but don’t send offensive or threatening text, voice, picture or any other sort of message, because it is a criminal offence to use a mobile phone to menace or harass someone. Also receivers can save messages and easily identify you as the sender.
Respect others' privacy when using in-phone cameras: In-phone cameras shouldn’t be used anywhere a normal camera would be considered inappropriate, such as in change rooms or toilets. You should ask for permission before you take someone’s picture. Also bear in mind that some venues do not allow the use of cameras and may refuse entry to anyone with one.
Ban the ring - not the phone: Wherever conversations are normally acceptable, venues can help by asking people to turn their phones to silent or vibrate mode rather than turning it off. This approach will help with compliance, especially for people who need their phone for important calls. Venues can also assist by reminding people to set their phones to silent mode, before they enter.