CoovaAP - Turn your Linksys Wireless Router into a hotspot

CoovaAP is an OpenWRT-based Firmware designed especially for HotSpots. As you know, you can inject OpenWRT firmware to the favorite Access Point Router “Linksys WRT54GL ver.1.1 to ver.4” . CoovaAP comes with the CoovaChilli access controller built-in and makes it easily configurable. CoovaAP is perfect for just about any HotSpot application - from WPA Enterprise (with RADIUS accounting) to Free Hotspot with Terms of Service acknowledgment and also commercial HotSpot captive portal applications. Use the embedded Captive Portal for a simple self contained HotSpot or use your own Captive Portal and RADIUS back-end.

Key features of CoovaAp are:

Based on OpenWrt, of course Open Source
Advanced Web-based Configuration
Easy HotSpot Configuration & Status
Embedded Captive Portal
Enhanced ChilliSpot Access Controller
Integrated ChilliSpot with WPA
OpenID Authentication
Centralized ChilliSpot Config (RADIUS)
WiFiDog Access Controller
PPTP VPN Client and Server
OpenVPN Client
Traffic Shaping

You can make integration with Wifidog also and make a centralize account authentication. In this case you only build a server as Wifidog Auth Server than plug to Internet and you can joint all Coova hotspot in any place in the world with any internet connection.
For Download and detailed installation instruction, please visit http://coova.org/wiki/index.php/Installation_Help
Download your Linksys firmware refer to same version and update through Linksys update firmware menu, restart and CoovaAP is ready. Do this update is make the warranty void.
My suggest is using notebook with battery enought when upgrade the firmware, 'cause this in upgrade proses need no any intrub till finish, otherwise your Linksys will not function anymore.