Via Retro Music Snob, I discovered these wonderful posts on Pop Headwound:

• Wilco - Rare Tracks, Vol 1.
• Wilco - Rare Tracks, Vol 2.

Not only are the tracks great, but PH provides a nice little explication of each track, with source and often links for more info.

These tracks should help hold you over until Sky Blue Sky comes out next month.

I think my favorite is actually Let Me Come Home, with Tweedy’s voice cracking and all.