College lecture, interview, or just plain spying, the iRig Cast ($40) attachable mic for the iPhone pretty much seals the deal when you need the brighter audio quality.  What’s really a big plus is that they throw in that serious looking stand, which can make all the difference in the world, and you get 2 free apps.  If you’re a musician, you will really pushin’ forty bucks a little too hard for those quality demos, but it might come in handy for some rough takes.