Google Goggles is now a feature of Google Mobile App for iPhone 3GS and iPhone 4 running iOS 4 or above. "In the new Google Mobile App just tap on the camera button to search using Goggles. Goggles will analyze the image and highlight the objects it recognizes -- just click on them to find out more.
You can see how this works in this short video:
Goggles works well for things such as landmarks, logos and covers of books, DVDs and games. However, it doesn't yet work for animals, plants or food," explained Google.
Google Mobile App with Google Goggles is now available in the Apple App Store. Just search for 'Google Mobile App' and download the latest version - it's free.