Anyone know how a person could homebrew a device with m0n0wall that is
similar to this?

http://www.zywall.com/products/model.php?indexcate=1111714398&indexcate1
=1123007871&indexFlagvalue=1021873683


I am mostly interested in the being powered off of USB port.  This would
be great to keep in a laptop bag for when being on the road.