I bought the New Scientist earlier this week which included this letter.

“Now that your best-ever-invention competition is over and there is absolutely no risk of being shot into space for doing so, I would like to pass on an answer from a group of people who should know. In 1978 BBC TV followed 12 volunteers living in a recreated Iron Age village in the Wiltshire woods. They left behind almost all modern technology and did their best to recreate every aspect of Iron Age living: rats, maggoty meat and all.

Twenty years later, the BBC brought some original volunteers together to share how the experience had changed them (and wring out an extra hour of cheap-to-make TV). The best-invention-ever question was one of those put to them.

Most of them hadn’t particularly missed modern life, and some were still living without a large number of 20th-century conveniences, but memories of a year trudging through authentic Iron Age mud had left them emphatic about one thing. The most important invention since the Iron Age is the wellington boot. So now we know.”

I would think the population of South yorkshire as well as the Glastonbury festival goers will agree with that.