There's an icon in "elive-center" -> "lanuage and keyboard configurator"to change the keymap but if you want a clickable icon and multi key-maps, you could install 'gxkb' which will give you an icon in the systray. Help: Add a second keymap on E16 - #7 by triantares
There's also a small uitilty to change a keymap on-the-fly I was working on but multiple keymaps have not been implemented yet.
Maybe I'll add that later today ..... I sort of stopped working on that script since it didn't look to fulfill any one's needs and @Thanatermesis seemed very set on keeping the existing "language configurator".
You sort of give me a reason to get back to it. 
Anyway if you want to have a quick solution (this is what the script will ultimately d,o too):
"setxkbmap -rules evdev -model evdev -layout ca, es, us -variant altgr-intl -option grp:alt_shift "
Which will allow you to use the keycombo 'Alt+Shift' to toggle keymaps.
In the above command I set simple 'altgr-intl' as a variant (for us) but if you want to know all available variants just run the above mentioned 'quick-keymap-changer'` and choose one of the maps.
The script will always allow you to bale out w.o consequences until the very last step.
