Nexus 7

Here's my experience on rooting my Nexus 7.

Needed debian/ubuntu packages:

aptitude install android-tools-adb android-tools-fastboot

USB debugging needs to be turned on (first become developper by tapping the phone version 7 times).
Download CWM-SuperSU-v0.97.zip, and put it on the SD card somwhere (e.g. in Download); md5sum db2f8032fd1df99c92d1bfff490a9217
cyanogenmod instructions for Nexus 7
note that fastboot needs to be run as root, otherwise it will just sit there with the < waiting for device > message)
Doing the fastboot oem unlock will whipe the device. Google calls it a 'factory reset', but the android system stays at the version from before the 'factory reset'.
This was the version of clockwork I installed; md5sum: c4bd5c94000a4e917a703583298532b4.

sudo fastboot oem unlock
sudo fastboot flash recovery recovery-clockwork-6.0.1.0-grouper.img

Right after that last command, select 'Recovery mode' from the boot menu (with Volume Down key), you'll now enter into the ClockWorkMod recovery menu. Select installing zip file from sd card, search for CWM-SuperSU-v0.97.zip you downloaded earlier, and install it. Then select reboot; ClockWorkMod will ask you whether you want it to make sure it isn't erased on boot. If you don't select this, clockworkmod will be erased the next reboot (that's what I choose though)
Install SuperSU, BusyBox
This procedure helped somewhat (though not a lot).

Rooting Android