If you found this page you probably already know that due to a dispute between Danger Mouse and EMI it would seem likely that 'Dark Night Of The Soul' will never be officially released. :-(
However as you are also no doubt aware NPR currently have a stream of the entire album. This obviously got many people thinking (me included), if you could capture the stream you could download the album.
Before I start I should preface by saying, yes this album has already shown up on various file sharing networks. However, it is not clear what the quality of that recording is. The tagging is certainly way off. Judging by last.fm scrobbles the most common tagging errors are on "Revenge" which is all of the Flaming Lips, not just Wayne Coyne (see the 'artist' tag on the NRP XML info file), "Star Eyes (I Can't Catch It)" should be credited as featuring David Lynch, the same for the last (title) song "Dark Night of the Soul", "Daddy's Gone" features Mark Linkous and Nina Persson, "The Man Who Played God" features Suzanne Vega, and the twelfth song is "Grim Augury" not 'Grain' (which makes no sense). Also the band name is "Danger Mouse and Sparklehorse" (see the official site). Finally, I would write out the word 'featuring' rather than 'feat.', which looks like crap. Another advantage of downloading via NPR is that depending on your own country's laws it 'MAY' (note I said 'may' .... in full caps no less) actually be legal to download a copy from the NPR stream (ask a local lawyer if you are not sure!).
As you know the NPR story can be found here. On that page are a number of JavaScript links to allow adding specific songs to your play list. Within each of those JavaScripts links are two nine digit numbers which are the keys to accessing the raw mp3 files. If you take these numbers and use them to construct new URLs (of the format below), you will be able directed to XML files that give you basic mp3 download URL information.
Here is sample to show how the URLs are constructed:
http://www.npr.org/templates/xanadu/xplayer.php?id=[First Number]&t=1&m=[Second Number]
Within the XML info files are 'MediaURL' tags. These contain the basis for a download URL. The bit that is missing is the domain name and initial directory. However I can tell you that this is "http://download.npr.org/anon.npr-mp3". Combining the domain name and initial directory with the Media URL, and then removing the unneeded section after .mp3, will allow you to construct the final download URLs.
Here is an example using the first song "Revenge":
Original JavaScript URL: javascript:NPR.Player.openPlayer(104129585, 104104364, null, NPR.Player.Action.PLAY_NOW, NPR.Player.Type.STORY, '0')
Constructed XML Info URL: http://www.npr.org/templates/xanadu/xplayer.php?id=104129585&t=1&m=104104364
Media URL from XML Info: /npr/asc/2009/05/20090514_asc_01.mp3?primaryTopic=1108&assignedTopics=1108,1104&aggIds=100920965,98679384,10001&orgId=1
Having already run through this process for all of the songs I can tell you that the rest of the songs just increment the number of the mp3, with one exception: The number goes out of sync at "Star Eyes" (jumping to 13) and then carries on counting as it was.
Here is the full list of songs for the Album "Dark Night of the Soul" by "Danger Mouse and Sparklehorse" (2009):
After downloading the files you will need to tag them. You can use the information above. It is worth noting that the official book does not use '(featuring [Vocalist])' as part of the track name, in the track listing.
Note: I worked this out using a combination of my browser (Opera) and Paros Proxy. However after doing so and running a few searches on google I later discovered this page and used that to clear up some of my own text. UPDATE: A search for anon.npr-mp3 on google demonstates that many people have worked out this exploit of the NPR server. Someone even wrote a User JavaScript (This doesn't work at the moment, probably because of minor changes to the NPR site).