I just found www.chippc.com, which has two lines of Au1500 based "thin
client" systems running windows CE.  One is the JackPC that fits in a wall
mount LAN jack and the other is in a small case (look under promotions for
a description of the lastest "Xtreme PC" models).  From a picture[1] and
specs (not identifying the chip specifically) they apparently use Silicon
Motion graphics chips.  They use DiskOnChip 32MB/64MB, and 64MB/128MB ram.
Both lines have at least 3 ports USB 2 and the top models go for somewhat
under $450US.  This looks like it could make a good NetBSD MIPS based
desktop system with well documented hardware.

[1] www.windowsfordevices.com/news/NS3139003780.html

Matthew Orgass
darkstar@city-net.com