More R&D on Cross-Compiling for the LaCie Ethernet Big Disk
This is all pure speculation, and is a personal brain-dump as I try to wrap my mind around soft-hacking this device.

LaCie maintains a Support Archive - specifically, they have a GPL Source Codes archive.  Unbundling the archive revealed the following:

drwxrwxr-x 12 lalee lalee 4096 2004-07-27 03:33 bash-3.0
drwxr-xr-x 30 lalee lalee 4096 2007-01-18 02:11 busybox-1.1.0-lacie
drwxrwxr-x 54 lalee lalee 4096 2003-12-03 11:44 db-4.2.52.NC
drwxrwxrwx  2 lalee lalee 4096 2005-01-27 14:24 ethtool-3
drwxrwxrwx  7 lalee lalee 4096 2005-06-04 09:44 ifplugd-0.28
drwxrwxr-x  5 lalee lalee 4096 1999-11-17 21:24 libcap-1.10.orig
drwxrwxrwx  5 lalee lalee 4096 2005-11-24 04:01 libdaemon-0.10
drwxr-xr-x  3 lalee lalee 4096 2004-06-04 05:14 liblockfile-1.06.1
drwxr-xr-x 18 lalee lalee 4096 2006-12-29 04:48 linux-lacie
drwxr-xr-x 10 lalee lalee 4096 2005-01-27 21:52 mDNSResponder-98
drwxr-xr-x 14 lalee lalee 4096 2007-01-01 22:59 netatalk-2.0.1-lacie
drwxrwxr-x 21 lalee lalee 4096 2008-02-03 23:05 openssl-0.9.7e
drwxr-xr-x 11 lalee lalee 4096 2007-01-01 22:50 proftpd-1.3.0-lacie
drwxr-xr-x  9 lalee lalee 4096 2007-01-01 22:52 samba-3.0.22-lacie
drwxr-xr-x 24 lalee lalee 4096 2006-12-29 04:59 uboot-lacie
drwxrwxrwx  6 lalee lalee 4096 2006-03-21 09:44 udev-088
drwxr-xr-x  3 lalee lalee 4096 2005-07-08 07:24 usbmount-0.0.14

On the surface, this appears to be a standard U-Boot bootloader.  At this point, I'm not sure whether U-Boot is configured to pull the Linux Kernel from the hard-drive, or from the flash part.  According to this blog site, the onboard flash is only 512 KBytes (Yikes!), and the RAM is only 64Megs (Argh!).  WIth such limited resources, I'm pretty confident that only U-Boot lives on the flash, and that the Linux Kernel is loaded from the boot sector of the first hard drive.  The LaCie will be cracked open shortly, and the drives hooked up to my real PC over the next week or two to figure that part out.

Update 2008-January-20
I have taken a renewed interest in hacking these routers, and will be taking another stab at rebuilding the firmware based on the latest source code available in the OpenWRT project's repositories.  I've given away most of my other routers to friends and family who either needed quick replacements for their dead Internet Routers, or needed something that operated in "Wireless Bridge Mode".

Thus, with all of my "Good" routers spoken for, I'm a whole lot more motivated to get some of these unused WRT55AG routers back into service.

Here's a Log-File Dump

Status Media Users Shares Disk Network Configuration  
		Date            Program                    Message
		May 3 20:10:48  syslogd                    started: BusyBox v1.1.0 (2006.11.03-14:53+0000)
		May 3 20:10:49  kernel:                    klogd started: BusyBox v1.1.0 (2006.11.03-14:53+0000)
		May 3 20:10:49  kernel:                    Linux version 2.6.12.6-arm1-lacie5a (root@lacie) (gcc version 3.4.4 (release) (CodeSourcery ARM 2005q3-2)) #1 Tue Oct 31 11:26:21 CET 2006