I am porting my echo layla 3G sound card to another machine (a superior quad core). The only problem is that it does not have any free PCI slots. I was wondering if there exists a reasonably priced pci to usb or firewire adapter that would allow me to plug in the echo pci card externally and port it through my spare usb or ieee slots (or some similar device)?

I think you need a PCI bus extender. I just Googled around and found the following

http://www.cyberresearch.com/store/computer-accessories-pc-peripherals/bus-adapters-expansion-chassis/PRO_600_3227.2.htm

No idea how good it is etc, and you'll need some kind of chassis to put it and the PCI cards in, may need additional power etc I have no idea how well these things work but I have heard of people using them. Aside from the link, I can't be of much help.

You know it's what I need (or close) but not at that price. It's cheaper to buy another PC. I didn't know what it was called though, so maybe there are reasonably priced options. Thanks

Or cheaper to sell the Layla and get an AudioFire.

Actually I think the reason for a bus extender is that you have more cards than will fit in the machine and they all have to be accessed by the same CPU{s), in which case the separate PC trick won't work.