I made an HTML port of game of life made with a table of checkboxes based on Pluralsight's Play by Play: HTML, CSS, and JavaScript with Lea Verou (http://www.pluralsight.com/courses/play-by-play-lea-verou). I was able to create a cool mousedown interface that allowed the "player" to draw on the board by dragging the mouse while it was down, and wanted to do the same for touch devices.
Unfortunately, touch events only hold references to the DOM element where they began (i.e. where "touchstart" fired) and do not recognize the DOM elements that exist under them (a detailed explanation for this can be found here: http://stackoverflow.com/questions/4550427/prefered-alternative-to-onmouseover-for-touch).
Instead, touch events maintain several lists of Touch objects - which represent interactions with the touch screen. Among these objects' properties are clientX and clientY, which indicate the X and Y coordinates of the events relative to the viewport (go to http://www.javascriptkit.com/javatutors/touchevents.shtm
