OpenFonera
After receiving my second La Fonera I was brave enough to flash OpenWRT Kamikaze. The used HOWTO described it very well and it worked without problems.
Now my first La Fonera serves a FON hotspot and my private (bridged) LAN. The second La Fonera is connected to my privat LAN via WPA over the first La Fonera. Now I can play with OpenWRT (Kamikaze) on my second La Fonera.
The described method uses the RedBoot shell. I don't know exactly how RedBoot works and wonder if it is possible to rescue the La Fonera in any case (wrong flashing, wrong configuration, ...). If anyone knows, please tell.