Over on my personal blog, I write about how to post photos from the iPad to ImageFields on a Drupal site. I intend to do so quite a bit this weekend on my visit to New York City (this will be my first trip without a laptop—yikes!).
I basically use Dropbox as a middleman to get a URL for the photo, which I can pass to FileField Sources so my Drupal site can use the photo. Unfortunately, for the time being, Mobile Safari doesn't support file select fields :-(