Convert! And accept iBooks into your heart! :)
Well, I'm sure it's been said and will be said many times, but get the free Calibre program and easily convert your .lrf's into epubs and you can stick them straight into iBooks. Or you can even make them Kindle files, although I'm not sure the Kindle app will let you read anything you haven't purchased. Stanza will though and will even let you use a computer running Calibre as a book server from which to download and read all your book library! Very cool feature and well worth checking out.