I finally convinced myself to have a go at installing the RootFS system described by fanoush earlier in this thread, as available from his site: http://fanoush.webpark.cz/maemo/#initfs.
After one initial set-back due to my inattention to his really quite detailed instructions (in which I had to reflash the operating system) I succeeded quite readily in achieving an effective install. On his website, fanoush offers a number of options for effecting the installation. I chose the one which he labeled the easiest: Alternative 2-3. In my successful installation I followed his instructions precisely, with one exception. I partitioned my 1-gig MMC and installed an ext2 file system utilizing "gparted" instead of the one he recommended, "e2fsprogs," as I was already familiar with using the "gparted" application.

The only minor tweaking I would like to see in my utilization of the system would involve the boot menu. On booting up the 770, the internal rootfs will be flashed as default unless you quickly press the menu key, in which case you're then given other options for which other particular rootfs will be employed. I would prefer that more time (maybe five or ten seconds) be given for this decision to be made. I looked at the bootmenu script, hoping that I might be able to modify it myself to achieve this delay. But I quickly realized that effecting such a modification would be too complicated for me to manage. Also, when one has a menu choice betwen flashing from the original rootfs and from the MMC, I'm not certain which option is preferable, and for which reasons. Is the rootfs on the MMC only there as a parallel back-up, in the event the main rootfs breaks down, or is it the other way around? And relatedly, as one modifies and adds applications, which of the two parallel root systems should be so modified, knowing that one of the two will not be as up-to-date as the one modified? These are conceptual concerns of mine, and should not detract from the excellent system fanoush has devised.