From 2007, the Apple iPhone has started the the foray of touch interface from mobile device to laptop and even big screen presentation. While no one can deny it intuitiveness, the physical touch by the finger to the screen surface draws few issues such smudging the shinny screen, and in case of presentation to big audience, the presenter needs to be next to the big screen, which requires limited size so the presenter can touch the screen. 
LM3Labs, a Japanese design lab has come up with touchless touch interface, where user can just float its finger in the air to interact with the desktop computer.