With another couple of taps, you're buying the song on iTunes or watching the music video on YouTube. You're sitting in some restaurant, bar, office or elevator you let the app listen to the music for a few seconds and marvel as it tells you the song title, singer, album and so on.

Shazam (free all smartphones): This app recognizes recorded songs-popular or not. That is, you can pull up the image of your scanned or photographed handwriting by typing a keyword into the search box. The accuracy isn't quite good enough to convert the writing into typed text, but it's good enough to let you perform searches on handwritten notes. If you snap a photo of something that includes writing (or paste in such an image), even handwriting, its behind-the-scenes optical character-recognition algorithms decipher the writing as text. Here's a taste.Д®vernote (free Android, iOS, Mac, Windows): Evernote is the popular notepad-of-all-trades app that keeps your notes synchronized across all of your gadgets. But the world is teeming with apps that recognize other sights, sounds and stimuli. You've probably heard of some speech-recognition efforts, like Apple's Siri and the dictation program Dragon NaturallySpeaking. That's when your phone or computer recognizes human speech, motion, visual cues and audio. And one of the most important areas for magic simulation these days is recognition. In my Scientific American column this month, I noted that in consumer electronics the promises of magic sells.

Phone app snap picture find item