2. When you are on a mobile, remember... other people can hear you, and more than likely they can also hear the person at the other end.

3a. Always work out the key sequence to change the phone back to English. There is always some comedian who changes it to German.

3b When being the aforementioned comedian, change the language to Arabic. Your victim won't even be able to guess the sequence to change it back to English.

4. A packed train is NOT the ideal location to play the end-of-conversation "no, you hang up first" game.

5. Never pretend to speak to someone on your phone. Your phone WILL ring and you WILL look like a complete idiot.

6. Never write anything dodgy in a text message, you just know you will send it to the wrong person.

7. Men should never agree to do something with/for their spouses via text message. it will be saved as evidence so you can't use the "I never did..." line.

8. Yes, the trigger happy, "HELLO?!" sketch was funny, it isn't when you do it.

9. Everyone has a mobile nowadays... there is no one to show off to anymore so turn the ring volume down.

10. Never answer a mobile whilst talking to someone, you instantly become a twat.

11. A crowded train is NOT the ideal location to show your mates your entire collection of the latest ring tones.

12. When a woman mentions that her phone has a vibrate function, do not crack the joke about it having a wipe-clean cover.

13. It is NOT necessary to buy the latest phone every three months or to buy this week's hottest phone covers or to download this week's number 1 as a ring tone.

14. It is NOT cool to send text messages to your mate on the bus/train/bus stop/train station/other side of restaurant table so that when s/he receives it, she can turn to you and discuss the content.

15. It is the height of laziness to call your mate three seats down on the bus just to save valuable effort in getting up and walking the distance to the empty seat beside him.

16. When in the cinema, switch off your mobile phone. Playing 'Name that tune' at the crucial moment of the film is not other people's idea of a good time.

17. When your mobile does go off in the cinema, do not instantly switch it off in embarrassment. Answer it and annoy everyone around you by saying that you are in the cinema and cannot talk long. Then give the caller a live account of the film. (Note to US readers: rule 17 contains sarcasm

18. When waiting on the train heading into town, always obviously lie to your wife at home. Everyone will laugh when you tell her that you have been kept late at the office and may be home very late. Naturally there will be someone on that crowded platform who has seen and recognised you. (Note to US readers: rule 18 also contains sarcasm)

19. When on the phone, don't talk loudly and project your voice to make people think you are important. Most people will think you are rude. Others will think you have a hearing impairment

20. Try to remember your ring tone. There is few things more irritating than an unanswered mobile phone because the owner has forgotten he replaced "Mission Impossible" with the "Hallelujah Chorus".