Assuming the media pc is a linux, couldn't you use netcat to pipe audio to the tablet?

My recommendation: +++

Big problem using a "stream the audio" approach.

LAG

But, this is how you do it...

Open VLC, and select media>streaming
Then, go to "Capture Device"
video device name = none

Audio device name = ***

then click stream...

make it HTTP, and type in your computers local IP, and a port. (lets say 172.16.10.2 and port 8080)

open this address on mplayer on the tablet (aka http://172.16.10.2:8080), and there you go.

There will be lots of lag, as the two players cache the data. So...




***
The capture device will me something like "Wave Out" or something. If you DONT have this, (Vista drivers have disabled this feature because they are jackasses) you will simply have to stick a wire from the speaker out into the microphone in, and use the microphone as the input device.

+++
Get a REALLY long extension cord, and plug in some headphones. It ill be a 3.5mm male to 3.5mm female, or a 1/8 male to 1/8 female.

like this: http://www.amazon.com/Cables-Go-1378.../dp/B00007FGU7

another way is to use shoutcast.
install shoutcast on pc
install plugin that captures audio out - and uses it as input for shoutcast channel

listen to (your personal) shoutcast channel on your n810 (via wifi).
shoutcast:http://www.shoutcast.com/download
line-in plugin: http://home.hccnet.nl/th.v.d.gronde/...WA2/index.html

No luck so far ^^
I just noticed I have an older VLC version so I will upgrade and try again
Thx for all the tips. the long cable is so far the winner but still, It would be a lot nicer to get it wireless, so I'll keep searching other options.
EDIT
ok I upgraded. I followed the intructions and ended up with this error
main error: cannot add this stream
main error: cannot create packetizer output (s16l)
main error: cannot add this stream
main error: cannot create packetizer output (RV24)
any tips? I'm currently fiddling with the options and looking in the internet for help, but I can't find the solution.
VLC announced me when I tried to connect with the N800, but the N800 itself showed nothing.
Thx
Elia

I want to do the same thing with my n810. I use an HDTV as my pc monitor and I have 5.1 surround speakers but at night I use my headphones. I want to stream the audio from my soundcard to my n810 over wifi while watching movies so the n810 acts as wireless headphones and I can watch from my bed. I would get a 3.5mm extension but my computer headphones and soundcard use a proprietary plug lol.

I tried VLC streaming but I couldn't get it working and it seems like it streams it but doesn't play it on the screen. I need the actual video played and the audio streamed

There must be a simple program that streams your soundcard output over IP

Yes, two of the three cheap ones I have do that. Not sure whether the third fails through design or manufacture. Unfortunately, there's no real way of knowing before you buy it. But they don't cost much more than a good (i.e. shielded) audio cable that long; here's one for $5, claims working distance 10-30 feet: http://www.dealextreme.com/details.dx/sku.12844
Being a car-based adapter, they've less incentive to short you on range (to prolong battery life), so it's likely to work.

Since you're looking to run it off a PC, I'm assuming you could rip that open and solder up an adapter to run off the PC's 12V; that's what I'd do. Maybe I'm assuming too much, though. Maybe one of these...
http://www.dealextreme.com/details.dx/sku.4053 Still only $9 total, where a cable's probably at least $3.

I've got a USB FM transmitter (it's a USB soundcard with fm transmitter built in) that I picked up off of ebay almost two years ago now (well, I bought another one of the same make about 6 months ago because it's awesome) that works very well for this sort of thing... the range you get out of it is set by the volume level on the soundcard; so with volume at 95% I easily get whole house (plus some of the neighbours), but I can also tune it down to like 50% to get good coverage in just one room without too much bleed over (at 100% volume it will completely block out other radio stations that are on the exact same frequency even at some distance, which can be a good or bad thing depending on the frequency and your desires!). It was a HiFast HFM7F... not cheap and probably overkill for your situation, but if you keep an eye on ebay they usually do an auction or two every week for one that you can end up picking up for quite a good price (I saw the "buy now" price and gawked, then picked up one from an auction from HiFast themselves the next week for like $12).

I'm wishing n800's BT profiles included audio headset profiles too. Then, not only could you listen to the PC remotely as this thread covers, but you could also make mobile phone calls as you could pair a phone with the n800/810 as an audio device.

I wonder why this audio function wasn't included. It would be a great feature.