Ubuntu – How to set a shortcut for “Always on Top” for window

As @jrg mentioned, this is still possible as Unity (Unity 3D, not the low-power 2D version) is largely built using Compiz.

You'll need to install the Compiz Config Settings Manager Yourself though. Precise steps are:-

1. Install CompizConfig Settings Manager using apt-get install compizconfig-settings-manager compiz-plugins-extra.
2. Run it (just type Compiz in the dash and you'll see it).
3. Click Window Management.
4. Enable the Put plug-in (select the check-box).
5. Click on Put.
6. Configure the shortcut for Put to next Output (click the pencil icon next to the keyboard shortcut for Put to next Output.
7. Logout and login again for the changes to take effect (from the comments!)

If you look at the file /usr/share/X11/xkb/symbols/latin, you will find the following lines:

key <AD06>  { [         y,          Y,    leftarrow,          yen ] };
key <AD07>  { [         u,          U,    downarrow,      uparrow ] };
key <AD08>  { [         i,          I,   rightarrow,     idotless ] };
key <AD06>  { [         z,          Z,    leftarrow,          yen ] };

So apparently an up arrow (↑) is already defined -- for ALT GR+SHIFT+U. If not, you can copy the file to a directory, edit it at will, name the profile somehow (say "foo" instead of "latin") and simply run

setxkbmap -I. -layout foo

(the -I. makes setxkbmap look for layout files also in the current directory).

The four strings assign to each key give the four characters that are produced by pressing the key, key with shift, key with altgr and key with algr+shift. The names of the entities (keysyms) that xkb can recognize can be found here.