This is an actual working example, not theory on how to do it. IMO, that's what makes it significant. Lot's of people talk about how this can be done, few show actual working examples (with source code) that others can re-create on their networks.
I use it when I need an ssh or web connection in extremely hostile environments that only allow free DNS queries out, like some planes, buses, establishments, etc.
There are also links to other implementations here: http://en.cship.org/wiki/OzymanDNS
Don't get me wrong, it's nice to see a simple example like yours, but projects like http://code.kryo.se/iodine/ do essentially (from an abstract perspective) the same thing.
scp localfile user@tunnelhost:/some/place