There's nothing trivial about it, it involves a multi-step process that this app eliminates with one click.
I don't see much difference. I did say that this is for jailbroken phones only, so if you've jailbroken your iPhone, you can easily run a simple ssh command? Am I missing something?
[1] http://www.engadget.com/2008/08/01/netshare-iphone-tethering...
The only difference with the app is the ability to trade one line of typing for $10.