So having been more and more annoyed with the selection of ports on the back of the G5, I decide to fill my two remaining PCI-X slots with USB 2.0 (A cheap VIA PCI card) and fire wire (A Sonnet Allergro FW800 64Bit PCI card). More interestingly in a previous thread (http://forums.macrumors.com/threads/2-0-usb-card-on-powermac-g4-mdd.1984177/#post-24113168) there was some confusion over these cheap USB 2.0 cards. I ended up buying one with VIA marked on the board but NEC written in the title and description (http://www.ebay.co.uk/itm/321818378916 example listing, there are cheaper ones) I can confirm that the sellers on ebay have it wrong these are indeed VIA controllers (surprise surprise) when you look up the vendor ID. However they are plug and play at least in a PCI based G5 on 10.5.8 (I might boot from the other HDD and test under tiger). I hope that it helps some people when looking to add more USB ports (as cheaply as possible) to a system. Edit: although further testing is required to fully test the capability of the via card as it maybe unstable.