Technology & the Queen's Peace: a survey

As preparation for a conference in the spring of next year, I want to carry out a survey. I need your help. I would be most grateful if you could answer the questions below. There are just three and you don't even have to answer all three if you do not want to.

You can post your answers below anonymously or using your name. Or you can email me (JonSHarvey@ymail.com), tweet me (either @JonSHarvey or @CllrJonSHarvey) or text or phone me (details here). I don't mind how.

In return, I promise to publish the survey results here as soon as I have a substantive pool of replies to make that worthwhile.

Now to the questions:

1) What existing technology (that you have come across) would, with substantial investment, be an extraordinarily cost effective way of improving community safety / crime reduction?

2) What possible technology (that is just beyond what we currently have) would, with substantial investment, be an extraordinarily cost effective way of improving community safety / crime reduction?

3) What 'sci fi' technology (that is well beyond what we currently have) would, with substantial investment, be an extraordinarily cost effective way of improving community safety / crime reduction?

You may well have more than one answer to each of these questions, but please try to restrict yourself to the best one, in your opinion, for each.

I look forward to reading your answers. Please spread this around to others who you think might also wish to participate.

Thank you!