Put on your Google Goggles. →
[More:] This is pretty cool. Take a photo of a landmark, a business card, an artwork, or a logo, and get Google search results based on the image.
I've been playing with this all morning on my G1 and it works about like they said it does- but I look forward to where they will go with this, when you can photograph the leaf of a plant to identify what kind of plant it is, or take a picture of a car and see what year it is, stuff like that.
There was already an app called SnapTell (which I think is on the iPhone as well)
that did this same thing with books, CDs, and DVDs, but they haven't been expanding it the way it looks like Google is going to do with Goggles.