Sneakernet Anyone?
Assuming this is a one time copy, I don't suppose its possible to just copy the file to a CD (or other media) and overnight it to the destination is there?
That might actually be your fastest option as a file transfer of that size, over that connection, might not copy correctly... in which case you get to start all over again.
rsync
My second choice/attempt would be rsync as it detects failed transfers, partial transfers, etc. and can pick up from where it left off.
rsync --progress file1 file2 user@remotemachine:/destination/directory
The --progress flag will give you some feedback instead of just sitting there and leaving you to second guess yourself. :-)
Vuze (bittorrent)
Third choice would probably be to try and use Vuze as a torrent server and then have your remote location use a standard bitorrent client to download it. I know of others who have done this but you know... by the time they got it all set up running, etc... I could have overnighted the data...
Depends on your situation I guess.
Good luck!
UPDATE:
You know, I got thinking about your problem a little more. Why does the file have to be a single huge tarball? Tar is perfectly capable of splitting large files into smaller ones (to span media for example) so why not split that huge tarball into more managable pieces and then transfer the pieces over instead?
There has been a proposal to add a new system call, reflink(), which would do exactly what you want. So far, it has not been accepted; however, ocfs2 (since 2.6.32) already has it as a ioctl ([1][2]).
A couple of articles from May 2009 on the subject:
An older variant of the idea was called COW Links.
Best Answer
Robocopy doesn't use any method to transmit only changed blocks of datas.
If you have to transmit your files thru a slow network, just use rsync.
If you have to transmit your files thru a "reasonable speed" network, no algorithm can speedup the process, because rsync (for example) have to read the entire file on client and on server to find duplicate contents. So if your network is Gigabit, or if you do a local copy, you just copy the files and voila. You can't get something better, execpted if supported by the filesystem (ala ZFS, but only works on the same partition).