I just had what's probably a silly thought.
as an alturnative to useing tar, what about useing a git pack?
create a git archive with no history, just the current files, and then pack it with agressive delta options.
since git uses compression on the result anyway it's unlikly to be much worse then a tarball, and since it can use deltas across files it may even be better (potentially enough better to cover the cost of downloading the git binaries)
this would be especially effective once git adds a 'shallow clone' capability to then take the snapshot pack and extend it (either forward or backward as requested by the user), but may be worth doing even without this.
thoughts?
David Lang