"""
First of all, there is only one version of the document, so no one is ever unsure if they are editing an old draft. [...] Second, version tracking is built-in so you lawyer can see what changes you made, and spend time looking at those changes rather than rereading the whole document.
"""
Wow, sounds like lawyers really need to learn about Revision Control Systems. I suppose they don't work as well (diff'ing, etc) on documents that are effectively big binary blobs (like .doc(x)) - but that just makes me think they need to learn how to use LaTeX ;-)
Incidentally, am I understanding these online 'e-signing' services (e.g., http://www.echosign.com) properly? Isn't a user basically trusting their private-key to the service?