I just updated the Extended Root Filesystem HOWTO with information on how to create and use a swap file together with an Extended Root Filesystem.

Since it's a file on the new partition, it won't be unmounted when the device is connected to a computer by USB. And as a regular file, it can be resized easily. It's a compromise between creating a swapfile and using a new partition for swap - which combines the advantages of both (and much more).

What's best about my way of (de)activating swap is that this works independently of the actual swap file or partition. The startup, reboot and shutdown scripts will work the same no matter if there's swap available or not. To add or remove a swap file or partition, simply modify /etc/fstab (after manually deactivating swap with swapoff -a), without having to touch the scripts again. Even if you decide against swap, it's enough to delete or comment out the line(s) in /etc/fstab, the scripts will keep working. I'd actually like Nokia to include something like that in their own system scripts with a future version of the 770's OS.

I hope you find it useful and welcome further discussion here.