This probably isn't the right forum but whatever.

I'm interested in an adjustable stem as I'm always swapping out bar/stem combinations. What I want to know is if anyone knows whether an adjustable stem that can be adjusted on the fly exists - like something I can adjust during the ride, without an allen wrench.

It would be sweet to be able to drop my risers mid-commute when i'm sprinting and raise them up when cruising without pulling over.