One of the first things I noticed when I participated in my first general election here in Utah is that many of the local spots are uncontested. You've got a Republican candidate just sitting there, with no Democrat challenger. (My tirade against our two-party system is something for another day.) It didn't take very long to figure out that if I actually wanted to cast my vote for some local government positions, I would have to vote in the Republican primary, since that's where there is actually a choice.
Utah Republicans have a closed primary, so you have to be GOP in order to vote. So, the next time a primary came around, I went to the polling place and registered as a Republican. I cast my vote, and the next day I did what I needed to do to change my status back to "unaffiliated."
This year, as you probably know, there's a lot going on in the world of politics -- on the local level and the national level. And the Republican primary this year is hotly contested, especially in terms of the Senate. Indeed, I received three different automatic calls reminding me that I could change my political affiliation to Republican in order to vote. Hooray for public records.
Apparently the GOP candidates want my vote! (Although I'm sure it's their mistake for thinking that my "unaffiliated" status means I'm leaning way right, rather than the other direction.) So I did my civic duty, and voted for the guy I'm most comfortable with, since I'm fairly certain that whoever ends up with the GOP win is who we'll end up with, no matter who I vote for in November.