Typing oddball characters in kubuntu

[Donn]

Yo,
I have heard-tell of mysterious ways to hold several keys down and then 
cleverly combine others (like R + O = R in a circle thing, or e + ^ = e with 
a hat symbol :) ) to get special characters that are not on a normal 
us-english keyboard.

What are your tips and tricks. Right now I am using K->Utilities->CharacterMap 
and copy-pasting -- which sucketh.

/d