Updated Wednesday, 3:12 a.m.
Handel's Messiah - Boston 2008. Handel and Haydn Society, Boston 2008 [no label, 3CD].
Live at the Symphony Hall, Boston, Mass., December 7, 2008. Very good FM broadcast.

As blogger Shelley Powers noted in comments below, these files are now gone after a takedown notice from the Handel and Haydn Society.

Commenters' reactions on the original post at the link are universally disappointed, with some pointing out the benefit to the Society of making this radio-quality performance widely available as a sample of what their $32, 26-track CD, professionally recorded in 2000, might sound like.

So how to give this gift, if you've got it in your head now?

Enter the MIT Concert Choir. At Wikipedia's Sound/list, you'll find 39 tracks of their performance of the first two parts of Messiah. (These tracks are a cleaner list -- no tables -- and point to the same files.)

Here's the Hallelujah Chorus. (These are all in the open-source "ogg vorbis" format, which your system's audio player and download manager probably recognize, even if you don't.

Wikipedia explains,

This is an incomplete list of full length copyleft/public domain musical works available on Wikipedia or Wikimedia Commons, with special emphasis on works that are (or should be) linked in Wikipedia articles. It may take a while for this page to load in your browser.

You can alphabetically sort each column by clicking on the small box at the top of that column (click again to sort reverse-alphabetically). If you have trouble playing ogg files, see Wikipedia:Media help (Ogg)...

This music is licensed under Creative Commons Attribution ShareAlike 2.0.

Here's the libretto.