Mobiles...

... the phone kind. Just don't get the fixation that people have with them. Apparently there's now a disorder where you think you hear your mobile phone ring / vibrate and it's not. Being a recent user (bought my first one 5 years ago and only recently upgraded to a handset that has all the bells and whistles - even MTV if I want it!) I just can not understand these slaves to a little bit of technology!
As my friends know I am terrible to get hold of on mine... it's either at home, run out of battery or temporarily in another dimension hiding from me! Or if I do have it with me I don't recognise the ring as being mine or in trying to remember which button to push to answer it, it clicks through to voicemail. Then people get mad at me cause they don't get hold of me, oh wow, some of the voice messages left I can tell you - if air could turn blue, it would have!
What really annoys me about mobiles though is that they're looking at you being able to use them on planes and the tube - good grief, if it isn't enough already to have the guy next to you on the train say "it's me dear (like she doesn't have his name in her phone), I'm on the 1801 (like I have been every week night for the last five years), and I'll be at the station at 1957 (as that train is every week night), see you then"!
The only use I can see is in an emergency, though if it's big enough the service crashes anyways, and to find all your mates at the festival, where 100,000 other people are trying to do the same and oh, the service crashes!