I want to isolate a subject's voice and very local sounds, but I want to simultaneously
record a proximal version, an ambient version and perhaps several subjects simultaneously in a sporting event. So, I'm looking at recording several tracks. More wireless mics still wouldn't solve the problem, as more tracks are still needed. An economical and durable solution would be body-mounted recorders with local microphones. The current crop of MP3/voice recorders com to mind. A 512 MByte flash card can record nearly an hour of uncompressed, stereo, 16-bit audio. So,
for under $200, I can cover a subject without worrying about electromagnetic transmission problems. The main problem would be synchronization in post production. A click track would work, but that involves some labor. I could sync the remote MP3 recorder clocks, but I don't know if any devices actually time
stamp their flash card files with sample accuracy.

Is anyone in this group doing this?
Any better ideas?

I'm not sure what you're asking. Do you want to know if it will sync? Yes, it will sync. Do you want to know if they have time code? I doubt if consumer recorders like those small recorders have time code. Their clocks may not be as accurate as a pro recorder.

We use MD recorders for our film projects, they sync up perfectly using Avid.

There is a good reason why professional recorders cost as much as they do. A 1 gig flash card is around $200 but a PMD670 recorder is another $700. Of course the Marantz pro MD and flash recorders have balanced intputs, phantom, limiters and filters. The file transfer is digital and with the flash memory drag and drop. By the time you interface a decent microphone with a consumer recorder you're into more money and with very little to show for it. (JMO)

A more reasonable approach may be to use a multitrack interface with a laptop.

I'm thinking about mounting these on bodies or helmets for martial arts footage. They have to be cheap and tiny.

Yes, I'm wondering about workflow for syncing the audio. I figured that I would let them run for a straight hour and use audio clicks to synchronize them. That is, start up all recorders,
do three clicks, let them run for an hour, sync up all files using the clicks. Do any of these cheapo MP3 recorders had at least an
accurate start time ? If not, I'll have to right some analysis/trimming software.