To whom thinks that the English lyrics to the Internationale look old-fashioned and unsingable, and translated in a too literarian language: Scottish radical rocksinger Billy Bragg shares your view, and so he wrote his own version of the lyrics. I think they are both modern and convincing. To read it, check his beautiful site at www.billybragg.co.uk, click on Songs, and find The Internationale. The song is in a really interesting EP with the same name, so take a look at the other songs too.
Together with Woody Guthrie's daughter, Nora, he also set the lyrics to many songs Woody wrote when he was still capable of holding a pen but not a guitar. The result was the LP "Mermaid Avenue", followed by a live CD from the tour that followed. The lyrics are obviously available on the same site. The second volume to Mermaid Avenue is expected to come out this summer.
Trust me: keep an eye on this guy! Travel wide and far on his site and report me any impression.