Here's a thought - as a way of sorting out this IED threat in Afghanistan, what about Mineseeker? Some of you may remember this - it was an airship fitted with a ground-penetrating radar. DERA (as it was) did trials with it, as a de-mining aid, and I think Virgin were some way involved too. Couldn't something like this be used to detect IED's? From what I remember of this thing, it was very successful in trials, even picking up very small anti-personnel mines.