United Kingdom International with Dead Keys
é apostrophe, then e
è funny ` on the top left of the keyboard, then e
ê ^ then e
ç AltGr+=, then c
To produce ^, `, ¸, ´, press the key twice.
Theres a nice little applet, the gnome keyboard indicator, that allows you to switch quickly
between layouts if you find yourself needing to type lots of apostrophes.
There are lots of other characters on this keyboard for European Latin-based scripts. Mañana.
From System/Preferences/Keyboard, you can print out the following keyboard map, which was how I eventually found the elusive ç.
|UK International Keyboard with Dead Keys|