can you use a USB hub to network 2 computers as alternative to using ethernet. i also saw a cable called a usb data bridge will that work?

if u have usb2 maybe, or it will

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What difference would USB 2.0 make except for faster transfers between the two machines? 1.1's 12 MB throughput should be adequate for most uses. 2.0's 400 MB thoughput would definately be better, but shouldn't be required for a simple 2 or 3 system network.

No you can Not, if you connect two computers directly USB to USB you probably will blowup your Mobo, since you connect live 5V and Ground between two independent Power Supplies

What you need is:

USB Direct connects Module (this is a USB cable that has a special Network module installed on it). Connect the two computers through the USB, install the Drivers and your are connected. This type of connection support only 10Mb/sec.

Like this: [L=Belkin USB Direct Connect Adapter ]http://www.usbworkshop.com/hardware/read.php3/250/info[/L]