Thanks to Kevin for pointing me towards the freaky-looking PD Audio system, which uses Windows CE PDAs with various add-ons to record at up to 24/96 quality onto SD cards. It seems to be a well thought-out system, and the site is useful, with what you really need lists. Unfortunately, it's not cheap. When you include their $549 digital mic preamp (but no mics), the top-of-the-line system costs $1,200+, with their 16/44 budget package at around $750. And of course, if you're on Windows CE, you won't even be able to run Bahji's Loops or Microbe software...