While the iPhone has a full-featured browser, using it with MWN is a less than optimal experience. You've got to zoom in to see what you're doing, and it's just a bit clunky. I never intended for My Writing Nook to be used from an iPhone.
I'd like to announce that My Writing Nook will soon be available as an app on the iPhone.
I'm very excited about this - the iPhone app synchs seamlessly with the web app, so that you can always have the latest versions of your documents with you. If you find yourself with a few minutes of down time, you can whip out your iPhone and write for a spell. If an idea strikes, you can jot it down quickly and synch everything up so that when you get back to your computer, your ideas are there.
It will be perfect for NaNoWriMo. You'll be able to add to your daily word counts from anywhere - standing at line, at the doctor's office, at the park.
I'm aiming to have My Writing Nook in the App Store in early October. Watch for updates here.