I was trying to run the pre-built binaries for Node-Webkit and was getting an error:

./nw: error while loading shared libraries: libudev.so.0: cannot open shared object file: No such file or directory

To fix this on a 64-bit system:

sudo ln -sf /lib/x86_64-linux-gnu/libudev.so.1 /lib/x86_64-linux-gnu/libudev.so.0

On a 32-bit system:

sudo ln -sf /lib/i386-linux-gnu/libudev.so.1 /lib/i386-linux-gnu/libudev.so.0

After that, Node-Webkit started up fine!