If you haven’t tried the html5 canvas tag yet, I suggest you give it a try. It falls under the same category as ActionScript’s Graphics and BitmapData classes. It is however much much simpler. One great thing about it is it runs really fast on IOS5. Have a look at some of these demos to see what I mean: http://zreference.com/projects/graphics/
A few days ago I recorded this short video tutorial… it’s very simple, but it will get you started if you’ve never tried canvas before: