On which finger had frodo the ring, when gollum...

[Amarie of the Vanyar]

In my opinion, it is not so difficult if you look at how things really happened, which is slightly different to the version given in the movies [img]smilies/wink.gif[/img]

but Sauron himself was overthrown, and Isildur cut the Ring from his hand with the hilt-shard of his father's sword.
The Council of Elrond, LotR

But Sauron was also thrown down, and with the hilt-shard of Narsil Isildur cut the Ruling Ring from the hand of Sauron and took it for his own.
Of the Rings of Power and the Third Age; The Silmarillion