Comon guys...throw the guy a bone. In 10 minutes this is what I found:
ASIX has a USB to Fast Ethernet product line. The Ax88172's product folder includes numerous schematics, layout files, and BOM.
Other companies like Silicon Labs offer similar chips. The CP2200 is used in USB to Ethernet bridges. There are some demo boards like the CP2201, but these are not as a clear cut solution as ASIX.
Another idea would be to modify the DEV-00042 from Sparkfun Electronics. The schematic is actually from a TI Application note. I think you could replace the MSP430 in this schematic with a TUSB3410 also from TI.