If you want a firewall that will fit on your bookcase then this is for you

With 3 NICs it makes a great firewall, providing RED, GREEN and ORANGE (DMZ) interfaces.

Features:

• Based on m0n0wall 1.3
• Dimensions: 170x50x225mm
• VIA C7 500 MHz cpu fanless
• 1GB RAM
  
• 256MB Compact Flash
  
• 3 10/100 network interfaces
• 2 rear USB ports
• 1 front USB port
• Mouse, Keyboard, VGA,2 Serial, Parallel sockets
• Onboard power supply
• External 12v power brick
• m0n0wall - web controlled firewall,serial console, stateful packet filtering, NAT/PAT, IPsec VPN, PPTP VPN, traffic shaping etc.
  

This system is a complete firewall including 512MB RAM and a Compact Flash Card installed with m0n0wall

m0n0wall is an easy to use firewall system controlled using a web interface - for more info see the m0n0wall website