I have heard good things about Git, as it allows you to synch and track changes via a local repository (which could be put on a usb key), and then later commit those changes to the central repository when you have access.
You can also do some interesting things like grouping changes for cleaner commits, but that and similar features seem beyond the scope of your needs.
So I would think it's definitely worth looking into depending on:
1) can git (either by itself or through some sort of plugin) parse the documents you are working on.
2) does the CLI to git scare your userbase?
I would also spend a few minutes and take a gander at flashbake.
http://wiki.github.com/commandline/flashbake/
it's built on top of git (so you get all that nice git goodness) but it is meant to be a source control system for writers, so it should be less scary.
-Terry
-----
"so listen up boy, or pornography starring your mother will be the second worst thing to happen to you today"
TF2: Spy
You can also do some interesting things like grouping changes for cleaner commits, but that and similar features seem beyond the scope of your needs.
So I would think it's definitely worth looking into depending on:
1) can git (either by itself or through some sort of plugin) parse the documents you are working on.
2) does the CLI to git scare your userbase?
I would also spend a few minutes and take a gander at flashbake.
http://wiki.github.com/commandline/flashbake/
it's built on top of git (so you get all that nice git goodness) but it is meant to be a source control system for writers, so it should be less scary.
-Terry
-----
"so listen up boy, or pornography starring your mother will be the second worst thing to happen to you today"
TF2: Spy