The iPhone Dev Team have updated their site saying they have a new version of Pwnage Tool and quickpwn. They have added instructions for us suckers with 10.5.6 to allow DFU mode to work again. Check it out for yourselves!
http://blog.iphone-dev.org/
EDIT: go to their "official torrents" section on the sidebar and it will show you the bittorrent links.
http://blog.iphone-dev.org/
EDIT: go to their "official torrents" section on the sidebar and it will show you the bittorrent links.