A startlingly beautiful, sharp and impeccably groomed young woman interrupted me as I questioned a man demonstrating 4g LTE links on the Hauwei stand at Mobile World Congress. I was trying to ascertain how they were going to play against Wimax, the wireless link being pushed by Intel.

The young woman, a Huawei employee who spoke rather better English than the demonstrator, said (implausibly I thought) that LTE is not going to rival Wimax, that they were addressing different markets. At least, that is what I think she said. I don't know for sure because she suddenly realised that my digital recorder was on, said that I should have warned her, and demanded furiously that I erase everything that had been said.

I complied politely, even though it was she who had spoken me, and my press badge was prominently displayed to warn her to watch her words if need be. But her sensitivity reflected the fact that billions are being staken on the future of wireless.

LTE proponents claim it is technologically superior to Wimax because it is newer. Both could coexist, with the same client cards able to cope with either technology and using whichever is most appropriate at the time. But it is yet another technological layer that users will have to pay for.

The young woman's attitude continued to trouble me, even though I felt she had overreacted. She was not Chinese, so it was hardly a case of lingering post-Mao paranoia. Perhaps she had a point.

It is possible with digital recorders now to record virtually everything that is said to you. At the end of a week in Barcelona I had perhaps thirty voice files of various people I had talked to, all in a tiny machine.

Among them were talks with speech-recognition specialist Nuance and a smaller company called Simulscribe, both of which offer technology that translates voice mail into text. The transcriptions are not perfect – though Nuance offers also offers a service through which you can have them checked by humans -  but the claim is that they are good enough to get the gist of a message,

What I need, I told Nuance's marketing manager Robert Weideman, is something similar on my voice files – or at least the ability to search them for keywords. The latest version of Microsoft's excellent One Note utility can do this, but so far as I know works only on files it has itself recorded.

It turns out that Nuance already offers the facility as a service and has considered offering it as part of its Dragon Naturally Speaking product. “We might well look at it again,” Weideman said.

It would be very useful for journalists and anyone else who has to take notes. But also a little scary because even with current technology it would be perfectly feasible not only to record your entire waking life, but also to index it automatically as well. It might help settle arguments about who said what to whom but you could see how some people would find it intrusive. Perhaps we should pay more attention to the etiquette of recording.

I’m back from Mobile World Congress now and have yet to write about a couple of the most interesting things there. So watch this space.