In a recent attempt to use the latest intel driver on my debian squeeze testing box to avoid a problem which is most likely described here:

https://bugs.freedesktop.org//show_bug.cgi?id=31367

So I needed only Xorg from the unstable repo; this is what I did:

The first step is to set up your /etc/apt/sources.list to include your typical Stable, plus the Testing/Unstable sources that you want.

Then edited /etc/apt/preferences:

Then I learned that debian also has an experimental branche, and the package i wanted existed in experimental only. When I started buidling on thes debian machine i used squeeze, so my apt file contained references to squeeze. From reading the apt en the debian docs I found that squeeze == testing, sid == unstable. So i had to rename all references of “squeeze” in the /etc/apt/sources.list to “testing” Ended up with this /etc/apt/sources.list:

/etc/apt/preferences: