In October 2010 Google released Google Goggles, a visual search application. Released in beta for Android devices and to iPhone and iPad users as part of the Google search app, Goggles uses visual queries instead of text or language.
In version 1.9, you can use the app to scan something of interest with your device and then search the web for a similar image. The app will scan its database to match up your image with one that has similar characteristics.
Google Goggles can be useful in a variety of situations. For example, if you are walking down the street and see an interesting landmark, simply take a picture and let Goggles track down information about the picture. While the app is not full proof and reviews about its accuracy are mixed, Goggles can be a valuable tool if used properly.