I have just today received this:
a Jetway Jetway JBC365 Fanless Dual LAN PC with quad core cpu.
Wedged a 4GB stick of RAM in (which passed 1 cycle of Memtest86) and also a 240GB Sandisk Extreme Pro SSD (SATA).
Only criticism is it's a bit fiddly getting the HDD cables to fold up nicely away from pointy pin headers, but after a few goes I found a reasonable way to lay them. You can stick mSATA sticks in but the chipset is a bit fussy and does not like all types of SSD (in particular it's not been tested with Plextor or Sandisk - the only 2 types I will touch).
But boy, it is *small*. I want it to be an Internet gateway, firewall, essential services like DNS, DHCP and critical filestore ( $HOME basically). The 2 gig ports lend it to that (though of course you could pull a VLAN stunt with one port).
It's running Mint linux 64 bit live right now and I'm stress testing the crap out of it. Bonnie++ results are good, got 8 cpuburn processes going at once and the temperatures are after about 1/2 hour (with room at about 20C and this thing has no fans):
Disk internal temp: 42C
CPU cores: 49-52C
System temp: 47C/27C (I suspect that is chipset/ambient board)
All of those have a very large margin before maximums.
When I've finished a badblocks run, I try it for feel of Mint - but I suspect it could also make a quite convincing media device (stapped to the back of a TV) or even a plausible desktop machine.
Only just got it so it could go bang tomorrow - but thought some folk might me interested...