Macworld’s Jason Snell explains why he recently finds himself writing on his iPad:

I’m no Oliver Sacks, but I’d wager that I’m just not taking more time to choose my words, but I’m actually using different parts of my brain when I write this way. And not only does the actual act of writing feel different, but the end result feels different to me too.

While I don’t use the touchscreen keyboard, I enjoy writing on the iPad as well.  Having my writing as the window, rather than a window, focuses me in unexpected ways.