I've been to Radio Shack twice to get a battery powered portable voice recorder that will just "work" on a Mac.
The first time, I bought the VN-4100 only to find that it won't work even in Virtual PC on a Mac. Win2000 and WinXP report an error trying to start the device, even with the supplied software.
The recorder has a 1/8" mic input, which I have to have. It's hooked up to a soundboard to record speech. The compression is wicked. 30 minutes 'high quality' mono 22.050 KHz MS 32 bit wav is only 6 MB on the device. If you hook it up to a pc it decompresses to about 30 MB when the transfer takes place. The VN-4200 will not work even on a pc without the software. And if you lose the disc, you're screwed because Olympus refuses to make the drivers available for download from their website.
I got fed up with having to find a pc to retrieve my files, so I went back and had the clerk open the package on a VN-3200 and connect it to a Vista laptop. The VN-3200 will mount as a usb drive without software, but it only has 128MB of memory [FAT12]. A 10 second test file came to 48kb, uncompressed. When I hook it up to a Mac, even without batteries, it just starts and mounts. Quicktime and VLC had no trouble playing the file.
It's almost impossible to tell from the packages what will work and what won't, which is stupid. If Olympus won't make software available over the web, then they need to be a lot more upfront about exactly their models will and won't do. There's like 10 different ones to choose from.
