Detecting that the browser has no mouse and is touch-only

I'm developing a webapp (not a website with pages of interesting text) with a very different interface for touch (your finger hides the screen when you click) and mouse (relies heavily on hover preview). How can I detect that my user has no mouse to present him the right interface? I plan to leave a switch for people with both mouse and touch (like some notebooks).

Detecting that the browser has no mouse and is touch-only

I'm developing a webapp (not a website with pages of interesting text) with a very different interface for touch (your finger hides the screen when you click) and mouse (relies heavily on hover preview). How can I detect that my user has no mouse to present him the right interface? I plan to leave a switch for people with both mouse and touch (like some notebooks).

Detect whether browser has keyboard/arrow keys in web page

I have a full-screen game in HTML+JavaScript, which uses the arrow keys as primary controls. This cannot be used on keyboardless Android devices (I haven't tested on iOS), and even if the soft keyboard had arrow keys it would take up unnecessary space. Therefore, I have added onscreen control buttons. However, the buttons are unnecessary (and absurdly large) on desktop browsers, so I would like them to not pop up unless they are needed.

How does the iPhone Google image search touch-event functionality work?

When I do a Google image search on my iPhone within the Safari mobile browser, it gives me this beautiful interface for flipping through the images. If I swipe left or right, it browses through the images. If I touch and move up or down, I get what appears to be the native Safari scroll function. Can anyone explain how Google does this? I'm only beginning to learn the Safari API for touch events. It seems like either you capture the touch event to attach handlers to swipe left or right or you let Safari handle the touch events natively, in which case you get the beautiful native Safari scrolling. Can anyone explain how Google captures left/right swipe but not scrolling?

iPhone opengl es: Touch detection

I have been messing around with opengl es on the iphone and right now I have some cubes on the screen. Currently I am trying to detect touches on these cubes. After a lot of searching on google this is what I have so far