A petition is not a vote, it's a public statement that "I support initiative X."

Gonna have to disagree with you (and everyone else in this discussion making similar statements). While the above is certainly the common understanding of what it means to sign a petition, from a deliberative process standpoint all it really means is that the question (in this case, "Should same-sex unions share the same rights and privileges as opposite-sex unions?") is worthy of consideration. This is distinctly different than "worthy of support." If you feel strongly about a petition (referendum, ballot measure, whatever) -- either strongly for or strongly against -- you should push to see it placed before voters. If for no other reason than to see where the issue really stands in the jurisdiction. (Maybe the overwhelming majority of Washington voters are raging homophobes -- this referendum will let the non-homophobic residents know where they stand.)

My point is that "supporting" a petition to get a measure on the ballot is not the same thing as supporting the measure itself. The danger of what these folks are doing is that most people will fail to make that distinction and treat anyone who signed the petition as a homophobe. I am not arguing that the petition signers should not be a matter of public record, only that the public should be educated that there is a distinction between supporting a petition and supporting the referendum.

I am not a resident of Washington, but if I was then I would sign the petition specifically so I could vote against the referendum. Trying to prevent decisive measures from coming to a vote is a losing proposition that engenders a lot of ill will on both sides. If the "No On R-71" crowd is convinced that they can win, they should push for the referendum to be on the ballot so that the supporters can see just how outnumbered they are.

Bzzt. You may want to check the history on the proposal. In fact, such a system was already "developed, implemented and OK'd" in Portland. From http://www.dailyemerald.com/news/ore-rep-floats-mileage-fee-to-replace-gas-tax-1.236118:

As the linked article notes, there were tracking issues because it was limited to the state of Oregon and had limited funds; the point of the new proposal is to expand the trial program nationwide so that folks can be tracked (purely for accounting purposes, of course) across state borders. From time to time, it throws out something stupid, too.

That being said, you're right about it not being the entire state of Oregon that has gone mental. Most folks in my home state are good people, whether they're raving liberal city-dwellers or raving conservatives from everywhere else. Oregon has a long history of being very progressive, from beverage container recycling laws to "death with dignity" (assisted suicide).