Hardware firewalls spare processor cycles on the main CPU, and offer better security, since they boot pristinely from read-only media each time. Other ultra-small, form-factor hardware firewalls based on Linux include SnapGears PCI-card firewall, the Arxceo Ally IP 100 and the Innominate mGuard.
The Yoggie Pico, unveiled by Yoggie earlier this year, crams a complete Linux-based hardware firewall into a USB gadget little larger than a typical USB thumb drive. It works in conjunction with low-level Windows drivers that sit below the TCP/IP stack, commandeering network traffic from all interfaces, and routing it to USB and thence to the Yoggie.
The Yoggie is based on an Intel PXA270 SoC (system-on-chip), the same chip that serves as the primary application processor in many high-end smartphones.