With all this perpetual talk about expandability, and dozens of extra slots on the spiffy new mac pro, I found my imagination falling short in imagining exactly what one might stick in there, besides graphics cards, and more USB/firewire. I hear that there are sound cards which expand your audio possibilities, and some graphics cards give you extra connections, but beyond these fairly simple cards, which only supplement the machine's already capable abilities, what is there PCI wise that actually adds a lot of new functionality? It all seems like a few more ports, or a different connection type. Is expandability all it's cracked up to be? P.S. I often found myself wishing my powerbook was more expandable, but that was because of USB 1.0, not owning a fast CF reader, and a limited number of ports. Also, the HD bays are nice, but I'm asking about PCI-Express cards.