Adjustable front fork trail

This is one of my favorite bicycle innovations. It's not an expensive or complex, just a novel, possibly useful idea. The picture shows a GT Tachyon from years ago that has an adjustable front fork trail. By varying trail you can make your steering more agile/agressive or more stable. Stable is good on the road touring or commuting around town. Agile would be for competition which would require more attention to control. There are lots of expensive innovations more or less necessary but this is one of the cheap ones