...didn't we use to have a cool technology thread or something? Anyway.
Intel Lightpeak. If, they do this right, (aka, not Firewire style), it's going to be awesome. And it's actually very close to being done ("shipping in 2010").
Basically, it is the USB idea, using optical fiber cables.
However even the initial version of it would have such a giganormous bandwidth (10gb/s and up), that you'd pretty much not need another cable.
So it could replace all USB cables. But it could also replace all HDMI, DVI, AVG and such cables. And even SATA and eSATA cables.
So you could finally have a case, that has only one type of ports on it and you would need just one type of cable to connect everything.
And they have already thought to include a copper wire along it, so devices like mobile phones / external hard disks would still charge / work.
(Power is something which you don't care how fast it arrives, as long as it does)
And because it would be fiber optics (light), it would have no electromagnetic interference and less degradation/distance, and you could have ultra long cables. Someone could have his motherboard on the basement, his hard disks on the first floor, and the display on the third, and the communication times between them would still be smaller than 1inch electric cables.
Oh, and Star Trek is proven right once again.
http://memory-alpha.org/en/wiki/Optical_data_network