MP3 Recorders?

ilbrec asks: "A friend of mine is a field biologist who studies frog calls. Recently when I was talking with him, he was interested in a MP3 recorder for his research use so that he can record the frog calls and analyze the sound on his computer later on. No, he does not care for DAT at all. He has one himself that he has so much trouble with. He is looking for a small device that takes at least 64 MB or so of solid-state removable memory that is easy to use. Sound recording quality does not have to be great, as frog calls can easily be analyzed at 96 kbps, according to him. No, he does not care for DAT at all. Does anybody know a good one?" Well, we have embedded devices that can playback MP3s...why not ones that can record live audio and use CompactFlash (or Smartmedia) cards, instead of the old cassette?