I'm going to make the argument that if you're a real libertarian, you're going to vote for Kerry. Consider that the Libertarian candidate has no chance of winning; you can't do any good by voting for him. On the other hand, a vote for Kerry will bring about a larger, more socialized nation with a more heavily progressive tax structure, increasing control over private industry and life, so on and so forth.
So why, you ask, is that a good thing? Why would I advocate helping Kerry win the presidency? Simple: His policies won't work, if they're really carried out long-term. Not that Bush is much better (he is - barely), but Kerry is bound, if he's able, to send the country straight into the furnaces of the firey down under (and we're not talking about the land of vegemite and boomerangs, here).
The end result of his twiddling and tinkering can be nothing other than the realization that government intervention produces the sort of problems that Americans abhor. From this point, perhaps real progress can be made.
Before you comment, just remember that this is very tongue-in-cheek. Now fire away, gentlefolk.