I'm learning Amazon Web Services and I have already used two hours in the process. I certainly see the need to use it for at least several more hours for learning. I will try Ubuntu this way, too - to see how it goes.

Creating another account, or ssh key, or whatever is certainly not worth the price and feeling unclean for cheating - even for me, unemployed student from the 3rd world. Because prices for instances start with 2 cents/hour. Good move for Canonical, anyway - 'free' is attractive, even if the usual price is 2 cents.