Wesgreen asked me about the Cowon iAudio 7 in another thread, and Since my answer is long I thought I should do a new thread.

iAudio 7 is FANTASTIC! The built in mic works well, but only records in .wma. Line in is not amplified, so it is no good for separate mic without a pre-amp.
It is Small and light. I carry it in my shirt pocket, and it doesn't try to pull my t-shirt off.
You can tell it to sort your content by file name or by folder hierarchy. File name is good for playing all music alphabetically, regardless of how many folders your songs are sorted into, while hierarchical sorting is what I use for podcast listening.
For example: I have a folder called Podcasts in it are .mp3 and .ogg files and another folder called More. In that folder there are more audio files and another folder labled Que. Inside my Que there are several more folders named 01(author name), 02(author name), etc... It will play every file in /Podcast (in alphabetical order) then play everything in /More. If I have put anything in /Que (usually old episodes) it will continue onto those, if not it will go straight into /01(authorname) and play whatever audiobook I have in there. If I finish that book it is smart enough to go back up one level and continue into the /02(authorname).
The display is beautiful, but too small for anything longer than short videos, or your eyes hurt, and it only plays one size/format, so video podcasts are mostly out too. I find the display mostly useless for anything other than file browsing.
The battery lasts forever. Seriously, it just never dies. I plug it in overnight about once a week, and it charges for about 10 minutes each morning as I'm loading podcasts onto it. I listen to it for probably 7-8 hours a day, no kidding. I keep the display dim, and I set it to black out quickly, but still it's impressive. I've had it for about a year, and there seems to be no change in battery performance.
It has auto shut off if I leave it paused for 10 min. or more, but when I turn it back on, it resumes at the same spot in the podcast/audiobook/song.
The volume is LOUD. The sound quality is reported to be great, but I have a mostly tin ear, and can not confirm that. There are WAY more built in audio enhancements than I can understand.
It has a sliding lock switch, but it has buttons that can still function while locked. This sounds stupid at first, but it is actually one of the best features. The buttons that bypass the lock are also semi-programmable as to what their function is while locked. It is really very clever.
The interface takes some getting used to. I think Koreans must read from right to left. It's the only explanation. Once you get used to it though, you will love it. I don't know what the kinds of buttons are called, but you only have to touch them, not push them. Not like the n810's touch screen either, they're really sensitive.
I have broken mine several times by sweatting like a pig into it, and gunking up the power/lock switch with concrete dust, but I've been able to repair it each time. Taking it apart SUCKS, try not to flood yours. The screws don't turn easily, but the switch is easy to take apart with a razor blade, and I cleaned all the contacts with a toothpick. Also I've worn down the headphone jack to the point that the left channel stops working, and I had to bend the pin back in with a sewing needle (no dis assembly required).
I'm sick of fixing it, so made a little plastic sleeve to keep it in and it stays dry now. It's more of a pain to get to the buttons, but life's made of compromise, isn't it?
One of the really nice little feature is that it has a little loop hole in it for a wrist strap, or those little charms that are required on cell phones in Japan. I put a small loop of braided fishing line (same as retractable badge cord) on it and a safety pin on that. Now I pin it to a seem inside my shirt pocket, and it never falls to the floor when I work upside down.
It also has a bunch of features that I don't use, and can not comment on:
Sleep timer, Wake up mode, FM radio, Picture viewer, Text file display, shuffle, wallpaper, lyrics, Fade in, Play speed, FF skip legnth. That's all that I can see or think of.
It can use MTP, or UMS for file transfer, AND it supports .ogg vorbis. As a Linux user, I appreciate that.
The video conversion software is windows only, but you could google to figure out how to do it under linux.
I will probably go for a SanDisk Sansa Clip+ when this one finally dies, because of .ogg support, price and expandability. The iAudio 7 is not expandable, btw, so buy it as big as you need it. I love this player, and I wish they still made them. My advice is to go get one at a good price while they are still available

If the iAudio 7 is like the iAudio U3, I can fill in a couple things:

The FM is outstanding. Locks on clean and clear, sounds great.

IIRC, you can change the FF skip length from 10-seconds-per-click (or 2 seconds?) up to 60-seconds-per-click (or 120?), and the higher FF rate is a lifesaver for long podcasts.

Sound is very good. (I use .ogg vorbis usually)

I find the track navigation confusing still.

At 1.15 ounces, the U3 is wonderfully tiny and solidly built.

what, it's discontinued already? nice repair job with the toothpick and needle there, pokey! the headphone jacks are usually the first thing to go, so i've taken to permanently glue phones to my players with Goop. fixed that problem. i've even done it to my N810, even though its jack is metal. because of that i had to stop carrying it in a pantspocket, but since it's now my most - used music player (because i'm dragging it around everywhere anyway) it's worth it.
regarding the mike/line input and using unpowered mikes, you can do a lot with adjusting the line-in volume. without a preamp bass frequencies seem to dominate, but just use a bright mike.
one other thing i like about my iaudio - linux and windows98 compatibility. i can't however use it, like my iriver, as a guitar practice headphone amp, since the G3 doesn't allow monitoring of line - in recording. too bad.
btw., please let us know if you get the 7 to work on the Nokia ITT with a powered usb hub! thanks very much!