Re: voice recorder
I tried two models, the Panasonic RR-US380 and the Olympus VN-960PC. The Olympus gave me better audio results, by far, and is the one that I kept to record lectures throughout nursing school.
Both models have a USB interface that allow you to transfer the file to your computer, where you can then do useful things with it such as transferring it to another type of audio player. In my case, after transferring to my computer I converted the file into an MP3 (takes up much less space that way!) using
Audacity CleanSpeech (free, OpenSource). Then I would transfer the files to my PDA phone and listen to them while working out or during my long commute to school, with the phone connected to my car stereo. Yes, it would be playable on an iPod or other music player.
The Panasonic had the appealing feature of including voice recognition software to transcribe your speech into text after transferring the audio to your computer. Unfortunately, in addition to recording audio inferior to the Olympus, the voice recognition software with the Panasonic doesn't do a good enough job to make it useful. Here's an excerpt from a dictated case history, with names asterisked out (even though the names weren't even correct!):
The most consultation far enough a consultation for self amounts the how am I LL, D. as in *** *** said ads evidence fanciers and client and analysis are still at *** ballots and an apple I've said today and *** think about the field-efficient mean this is the fifth year old man & clinic with the blame some audio, named *** *** what pressure blood pressure 17 era<head 9¢ and maps of the case then-message last hysteria, hypertension and diabetes data dispatching separate the behaves the hyperplasia and high tech *** layman message medications include both are planned 55mg daily *** full 0.5mg. Access medfly then man who could reveal his ankle and yen big advantage of this kind of thing intimate and advancement case and 
Interestingly, the software seems to know somehow if the file was recorded on the Panasonic. I was not able to get it to take a stab at processing a recording from the Olympus.