In my ongoing quest for replacing flash wherever possible ( :) ) I found ExplorerCanvas, a JavaScript library which emulates the canvas object of Firefox, Safari and Opera ( whatwg specs) in Internet Explorer. It's not the fastest thing on earth, but for little tasks (like rotating bitmap images and drawing graphs) it could be a useful library. Here are some examples (works in IE, Safari 1.3/2.0, Opera 9 and Firefox 1.5):

Rotating image

3D Animation

Bouncing Balls