Here in Canada the voting age is 18. Yes, some 18 year olds are in no way educated enough to make a decent decision, but we can't do anything about that without making frightening changes to democracy. On the other hand, what we can do, is let younger people vote under certain circumstances. I knew a guy in grade ten who was more involved and educated in politics than (almost?) all of you combined. I figure that by the age of 15 or 16, if people want to, they should take a test allowing them to vote at an earlier age.
The only issue with this idea: who controls the test? This is quite serious: whoever is in power cannot control this test :o
All I can think of is setting up extremely unbiased questions, such as listing a couple of Canada's top 5 export countries, the names of political leaders, names of provinces, etc. This should should be a very simple test; anyone who actually cares to try, should pass.
I also suggest that the official opposition party can suspend this new rule at any time, if they find the tests to be biased. I can only assume this move would not be taken lightly by citizens, but it does give everyone a say in what goes on the test. I suspect that if the opposition suspended the test because minors were most often voting against them, that would be a powerful statistic to point a finger at them in future elections.
As an argument against this, I won't accept this fallacy of bifurcation: Oh noes, next will be mandatory tests for all voters!