Netchip manufactures a range of USB devices, including the 1080, which provides direct connection between two USB hosts.
In addition to selecting this option to either be compiled into the kernel or to be build as a module, you need to configure the appropriate networking interfaces. If you have two machines (say zhora and rachel, then on zhora you would enter ifconfig usb0 192.168.0.1 pointopoint 192.168.0.2. On rachel you would enter ifconfig usb0 192.168.0.2 pointopoint 192.168.0.1. To test that it is working, on zhora, enter ping 192.168.0.2. If you get packets back, it is working correctly.