Some blog post take a little longer to write and this was certainly one of those. It wasn't so much the writing but the building of the tools and tool-chain, running all the tests and scripts, and just to get things right.
The Fonera 2.0g (FON 2202) became available in Europe (on April 21st) and an all new 2.0n (with 802.11 N support) is expected to arrive in Europe as well as here in the US (US$ 99) in October, making this the perfect time for a discovery mission into the Fonera FON 2100, which isn't a very complex piece hardware but still a very capable device.

The La Fonera 2.0 (FON 2100) doesn't come with ssh enabled but its RedBoot v1.3.0 boot manager, which is based on the eCos real-time operating system Hardware Abstraction Layer (HAL), allows for downloading and execution of embedded applications via serial (X/Y-modem protocol) or Ethernet (TFTP protocol); there are plenty of sites that provide detailed recipes on how to get the Fonera into a state, where its bootloader becomes accessible.
RedBoot makes it easy to replace the currently deployed heavily customized Linux distribution with a more commonly used Linux distribution for wireless devices, like DD-WRT or OpenWrt.

During booting, the FON 2100, waits at IP address 192.168.1.254 on port 9000, for about 10 seconds, to receive an interrupting Control C. Meaning, if a host computer with an assigned IP of something like 192.168.1.2 is connected to the Fonara, issues this command:

echo -e "\0377\0364\0377\0375\0006" >break.bin; sudo nc -vvv 192.168.1.254 9000 < break.bin; telnet 192.168.1.1 9000

and the Fonera gets rebooted, RedBoot will pause the boot process and show the RedBoot> prompt.

Depending on the host's OS, this can also be done, by simply launching telnet 192.168.1.254 9000 and pressing Control C. However, it may be necessary to re-configure telnet a little, for instance by putting this .telnetrc file in the user's home directory.