h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The usual emissions I hear are "I'm on the train, we're just leaving (insert name of a station here) now. I'll see you later"

At least they can't be used on the underground yet. Though there are plans afoot to enable a service there. If it does go ahead no one will be able to hear a thing and there'll be a lot more shouting -average noise level on a tube train VERY high.

I've never been on a tube train...

Then you won't understand that Phil is exactly right - and that phones should be banned on trains (both normal and tube) where people use them to discuss the fact that they are on a train and what they should get on the way home from the station/what the person on the other end of the line should cook for supper...

The Tube is the common name for the London Underground* and it can get very noisy when two trains are going in opposite directions on each platform. There are some train companies which don't allow mobile phones in certain carriages.

*for more info on the underground see http://www.h2g2.com/A48502

There should be an automatic reply service that simply relays the fact that you are on a train and leaving ...[the last station].. If the caller wishes to discuss something else, they can press 1, if they are happy with the given info, 2, and if they wish to speak to an operator, 3. Or an even better system would be a service that randomly connects the caller to any mobile (and not the actual called phone). This would confuse everyone so much that the mere question of "where are you!?" would become confined to the past. It would also cause much amusement.