I hate reading "txt speek", so refuse to inflict it on others. So, I always seem to end up sending 2 or 3 messages to say what these people manage to in 1. But I have seen people sit there spending a minute or two editing their "txt spk" messages in order to save the 5 pence it would cost them to overlap onto a second message. Or the 1 pence or so it would cost to CALL the other person and convey the necessary information VERBALLY!
I have seen worse though: in 1998 there was some information going round (never found out if it was true or false) that the first 2 seconds of a mobile call were not registered by the network, to allow for those situations where you get to voicemail and hang up quickly. Some rather tight people I knew would make one-word phonecalls to each other to try and make use of this. I remember sitting in a kitchen with a girlfriend's flatmate, who was cooking her dinner. Her phone would ring, she'd hold it to her ear and hang up. Then she'd ring back and say "Yes", then hang-up. Then again, "Mona and Lucy". Then again, "cooking". And so on