In Australia we have compulsory voting. Everybody has to get off their arse and do it (or at least go to a polling place, take a ballot sheet and stick it in a box, you can leave it blank or draw a penis on it if you want).

Personally I see both upside and downsides to it. On one hand it's a violation of my right not to vote, but on the other hand that's one of the more minor violations which the government by necessity commits anyway. The upside is that it leads to more moderate politics -- there's no need for the parties to appease the "base", so they always wind up fighting in the centre.