I'm right in the middle of a project that needs something like this; I assumed I'd be rolling support for it myself. This should save me a quite bit of time, although it only implements half of what I need (the other half being merging local changes back to the remote resource when back online). Thanks for the pointer!
I would think that this would be a fairly application-specific system, and thus jQuery or other popular frameworks wouldn't be able to provide a method in a fairly abstract way.