I just bought a Sony Voice Recorder (ICD-U60) and it was a surprise for me that is incompatible with my iMac. It comes with an installation disk for Windows but the Recorder has a built in USB.
Here's what I did. It's a bit of a pain to set up, but works fine. I have Windows XP running in a partition with Bootcamp on my Mac. I seldom use it, but it does open and run fine. I record voice notes on my Sony IC recorder, and boot the computer in Windows. I downloaded a free shareware program for Windows called Switchsetup.exe. It converts just about any file format into any file format, so can convert the voice recorder file format into an MP3 or WAV or whatever you want. You just drag and drop the file into a window. I converted my voice notes to MP3, and it automatically puts them into the My Music folder on the Windows side, which I never use for anything else. Then I switched back over to Mac OS, where I can see the My Music folder in the Windows partition. I created a Mac OS alias of that folder, and drag it onto my Mac desktop. That way, I can easily access all the converted voice notes while using Mac OSX, once they have been converted in a batch process on the Windows side.
Once set up, this works pretty easily. If I have a bunch of new notes on the IC recorder, I run Windows, convert the files, then go back to Mac OS. When I click on the My Music alias, I get access to MP3's of my voice recordings. Click on them and they get pulled into iTunes where I have a "playlist" labeled My Voice Notes. Once there, it's easy to listen to them or do other things, include editing them in other software if I want, etc.
We really do need a voice recorder add-on for iPods and iPhones.