I've now ported Bill Paul's FreeBSD kue(4) driver to NetBSD.
It supports the following USB-Ethernet adapters:
           3Com 3c19250
           ADS Technologies USB-10BT
           ATen UC10T
           D-Link DSB-650
           Entrega NET-USB-E45
           LinkSys USB10T
           Netgear EA101
           Peracom USB Ethernet Adapter
           SMC 2102USB
           SMC 2104USB

Check out the man page for more info.

Again, the driver is not so well tested, so tread carefully.

--

        -- Lennart