Is ethernet much slower that USB 2.0?

I have been told ethernet to a networked computer 6 feet away would be WAY faster than USB 2.0 to a Seagate FreeAgent 250GB HD. I just created two images of my HD using both. The ethernet took 2.5 hours. The USB to the HD took 31 minutes. Is USB 2.0 much faster than ethernet or do I have something wrong with my router or some other problem?

usb IS faster

USB is the faster interface. However, where the ethernet connected HDD comes into its own is that it is accessible from ALL machines connected to that network whereas a USB connected device is only accessible to the machine that it is directly connected to (and to the rest of the network if sharing is enabled BUT only if the host computer is switched on).

Thanks guys. I thought I had a problem. That does explain what happened. Sound like on a home network....my little Seagate 250GB USB HD will be just fine. I have only had it for 6 hours and I love it already. These are good little drives for the $$. Got mine at WalMart on sale for $67. Wish it was 7200 rpm though.
Walmart.com: Seagate FreeAgent GO Portable Hard Drive, 250GB 5400RPM - Sky Blue: Computers