How do I change keyboards from the command line?

You can find all the different keymaps in the following locations:

/usr/share/keymaps/i386/
/usr/share/kbd/keymaps/i386/
/usr/share/X11/xkb/symbols/

To change the keyboard layout (e.g. to Spanish) in the Linux command line, type the following command:

loadkeys es

For X:

setxkbmap es

To make these changes system wide, assuming you’re using Ubuntu, you can use the following:

sudo dpkg-reconfigure console-setup

From terminal

English to Hebrew and vise versa with Alt + Shift

setxkbmap -option grp:alt_shift_toggle us,il

You can see all locale alias with this command

cat /etc/locale.alias

More info about setxkbmap in manual

man setxkbmap

Ubuntu 13.10 or Later

This works better then setxkbmap with Gnome/Unity keyboard layout indicator.

gsettings set org.gnome.desktop.input-sources current 0

0 is the layout index (0 default or top layout). Layouts indexed starting from 0.

For easy use, create an alias.