I have seen many of the posts on here asking how to make backing tracks (and whether it is possible to download the ones from the lessons - which you cannot, right now anyway). I found a really good source for drum and bass backing tracks for a bunch of popular songs. I found it on Soundclick.com, which is a place for people to post their music. The 'artist' in particular is "Noiz in Da Basement." They tell you how they made the tracks, andthey provide them on Soundclick in Mp3 format for free download. These are perfect drum and bass backings -- all guitar and voice parts have been removed.
If you go to their site --
http://www.medic129.com -- you'll find the mp3 tracks (which require a Soundclick.com registration to download), and ALSO midi versions of the same songs. Really good midi.
If any of you have a Fender G-DEC amp, you can simply transfer the midi versions to the amp and use them as backing tracks like that.
These are the best I've found -- most 'backing tracks' leave the rhythm guitar in, so you may be able to 'jam', but 85% of the guitar sound on most songs is the rhythm part, and most of us on here need to practice that, as well.
I'm not 'promoting' Soundclick.com or the guys that made these tracks - it's just that I've also been on the lookout for something I can make my own guitar sound to, with only drums and bass, and without having to be a Cubase or Nuendo expert to do it.
Almost forgot...a HUGE shout-out to Gabriel Leopardi -- awesome lessons, and what a great, versatile guitarist!! I can only hope that my practice makes me half as good a guitar player as him