Apple:

Install the free iPhone 2.2 Software Update and get Google Street View, public transit and walking directions, and more.

What’s in this update:

  • Enhancements to Maps
    - Google Street View
    - Public transit and walking directions
    - Display address of dropped pins
    - Share location via email
  • Decrease in call setup failures and dropped calls
  • Enhancements to Mail
    Resolved isolated issues with scheduled fetching of email
    Improved formatting of wide HTML email
  • Podcasts are now available for download in iTunes application (over Wi-Fi and cellular network)
  • Improved stability and performance of Safari
  • Improved sound quality of Visual Voicemail messages
  • Pressing Home button from any Home screen displays the first Home screen
  • Preference to turn on/off auto-correction in Keyboard Settings
Details on the features

Google Street View - Street View takes you on a virtual walking tour: Navigate street-level photographs of places you've located in Maps.

Public Transit and Walking Directions - Get walking directions, find public transit schedules, check fares, and estimate your travel time.

Share Location - Tap the Share Location button to send an email that includes a Google Maps URL.

Podcasts - Get access to millions of free podcasts on the iTunes Store via Wi-Fi or your cellular network.

Safari Improvements - A new search-friendly user interface, better performance, and more stability make Safari even easier to use.

Home Screen Shortcut - Take a shortcut from any Home screen back to your first Home screen by pressing the Home button.

It works for the iPod touch as well, of course. And there are apparently a lot of security fixes as well.