Yes, there is more than one way to approach it. See 'optimistic' pathcoin in my most recent post on the mailing list.
Several related ideas; lifting off chain, 2 party, just presigned tx chain, private pathcoin (what you see in that PoC code).
You may also find the slides from my Adopting bitcoin talk interesting:
I don't see anything with amazing utility yet. Maybe 'cold channels' is interesting.