I don't know who came up with it, but the idea is brilliant: the washbasin has a foot-operated tap. This allows you to rinse your hands without touching the tap with your sambaar-chutnified fingers. Moreover, you don't need to remember to close the tap when done, a common problem in public washbasins. Regulation of flow is fairly intuitive and corresponds directly to foot pressure rather than turning a tap in circles.
Why don't we have more foot-controlled taps? Why is MTR the only place where I've seen this? And why, despite having a phone with a camera, did I not take a photo for this blog?
Update (16 Feb 2010): Saurabh clicked a photo of the tap which can be seen here (you may have to use your imagination a little :-) )