Taping With The iPod - Using Apple's iPod As A Recording Device - Belkin TuneTalk Stereo Review
And Wired magazine has its How To Wiki on the same subject... I'd copy it here (I think they allow that for non-commercial use), but I'm providing the link to it as well as it's constantly changing (as Wikis are wont to do): Lay Down Tracks On Your iPod (Wired HowTo Wiki).
- Using the barely noticeable line-in jack on Belkin's TuneTalk accessory, singer-songwriter Jimmy Camp --> recorded his entire Captain America album on his iPod. You can use your pocket player as a one-track recorder too. Just remember: Camp's technique prevents post-recording level correction, overdubbing and sampling, so you'll need to play guitar or keyboards while you sing (or invite someone over who does). Here's what he did plus a few bonus suggestions from some savvy readers:
1. Use three microphones: one for the main instrument, one for your voice, and another to pick up ambient room sound. Connect them to a simple mixer and route its output to the TuneTalk's stereo input.
2. OR use three identical portable recording units and mix the recordings down to stereo on your PC (using freeware like Audacity). This will allow you to level voice, main instrument and ambient sound much better, plus you do not have to operate the mixer while recording. As a simple mixer costs as much as two basic portable recorders, the cost is the same.
3. OR buy a multitrack audio interface --> for your pc/mac, which should cost less than 2 Ipods. Cheap mixers can be had new for less than $100. Buying used off craigslist will get you more for your money.
4. VERY IMPORTANT: Check your levels. Since you're recording all instruments to one track, ensure your mixer's volume levels are set correctly; you can't go back and turn up the volume on the guitar once the recording is made.
5. Do lots of takes. You're not paying for a studio or engineering help -- the trade-off is tons of trial and error.
6. Try different rooms. Record all over the house (including the bathroom) and experiment with adding or removing rugs from a room's hardwood floor.
7. Get it out there. Camp recorded all 10 songs and submitted them to iTunes within three days. He insists you could really do it in one.