Thanks, FileMagnet
The new tilt-scrolling icon in Instapaper 1.4 was designed by Joshua Keay for FileMagnet, and he offered it to me for free. Thanks, Josh!
FileMagnet is the only other application I’ve seen that implements tilt-scrolling well. If offline access to a collection of your own files (Word, Excel, PDF, photos, music, movies, anything) is your thing, give it a try — it’s much more suited to that role than Instapaper (which is optimized for web pages), and it’s a very nice app.