Many people have heard of Shazam, but if you haven't...

You press a button and it listens to whatever you're listening to. Then it tells you what the song title is, the artist, lyrics, and can link you to where you can buy it on iTunes (I don't).

Sometimes it takes 5 seconds, sometimes less.

I listen to a lot of songs in languages I don't know. Shazam does. I can go into my Shazam history to see all of the songs I, um, Shazamed and I can add them to my spotify. I love it. Highlly recommend.