Todd Barnes at Toughturtle has some interesting web apps for the iPhone, including the often breathtaking Nasa Image of the Day.

Description of NASA Image of the Day:

NASA Image of the Day specifically formatted for the Apple iPhone and iPod Touch mobile devices. Get daily images from the “NASA Image of the Day” gallery automatically from the NASA web feed.

The web-app will display:
- The image title.
- The image description.
- The time the image was updated by NASA.
- A link to the full description and a full-size image.

- NASA RSS Web Feeds such as Breaking News, STS-124 Mission Updates, Moon and Mars Exploration News, Shuttle and Station News, and many more!
- NASA podcasts: Original audio podcasts from NASA.