As advertised on Daringfireball.net, Memos is kind of amazing. When it works. The iOS app scans your photo library (on the device, not on someone else's computer) and recognizes text. You can then search for photos with text.
Here's an example I tried. I searched for "Fainting"
I found a photo with a sign in the background.
That's Bladerunner level stuff.
Unfortunately it doesn't always work. The app reindexes at every launch and often does not find the same text later. I tried to demo the app to a friend and was left looking like a crazy iPhone person. In the example above, searching for "goats" does not find any results.
Even with all of these issues, Memos is a great technology demo and possibly an insanely useful app. I love the idea that taking a note is as simple as snapping a photo with the defauly iOS camera.