Tomato USB is an alternative Linux-based firmware for powering Broadcom-based ethernet routers.
It is a modification of the famous Tomato firmware, with additional built-in support for USB port, wireless-N mode support, support for several newer router models, and various enhancements.

Supported Routers
Tomato USB supports many Broadcom-based routers from Asus, Linksys, Buffalo, Netgear and other manufacturers.
See the documentation about the different build types for more details and for the list of models supported.

Features

Firmware replacement with full LAN/WAN/WiFi support
WiFi 802.11a/b/g/n, Dual-Band, LAN up to Gigabit
NAS support: external USB storage, with file sharing on LAN and WAN (supports FAT/FAT32, EXT2/EXT3 and NTFS)
Print server: access USB printer from LAN
VPN support (through OpenVPN, both client and server mode)
Media server DLNA
Nice and easy to use GUI
Installation of custom packages from Optware (P2P clients, proxy, web server, etc.)
Graphical bandwidth usage monitor
Very advanced QOS configuration
Access restrictions
Advanced wireless configurations (WDS, wireless client modes, etc.)