rings:

germany: right
poland: right
serbia: right
spain: right except blah, where they wear it on the left
india: man - right, woman - left; worn at engaugement time
czech: left
portugal: left
united states: left
italy: left
lithaania - right

bulgaria:
russia:
china:
japan:
croatia:
bosnia:
greece:
turkey:
solvinia:
france:
england:
ireland:
scotland:
mexico: