Another option that is similar to the Zoom in that it's a single mic and doesn't require an interface, just run it into an iphone or other portable device:
http://www.audio-technica.com/cms/wired_mics/50c0cbe703025c75/index.html
"Combining high-resolution audio with increased connectivity options, the AT2020USBi cardioid condenser microphone adds a new level of sound-quality and convenience to the expanding lineup of Audio-Technica USB microphones. Modeled after the critically acclaimed AT2020, this digital output mic features an A/D converter with a 24-bit/96 kHz sampling rate to deliver high-resolution articulation and intelligibility that’s perfect for home studio recording, field recording, podcasting and voiceover use.
The AT2020USBi works with both USB and Lightning cables (included), so you can use it straight from the box to digitally capture audio on the device of your choice: PC, Mac or lightning equipped iOS device. The integrated gain control adds to the convenience, allowing you to adjust the input level directly on the microphone.
The AT2020USBi cardioid condenser microphone brings state-of-the-art sound for the on-the-go lifestyle to the family of Audio-Technica USB mics"