Inspired by the tilt scrolling feature in the Instapaper iPhone app, I decided to go ahead and make a bookmarlet to enable tilt scrolling on any webpage using the JavaScript deviceorientation API and its Firefox counterpart.
You can install the Bookmarklet in Firefox 3.5+ by dragging this link to your Bookmarks Toolbar:
In Mobile Safari, copy the following text and replace the Address of an existing bookmark with it: