I just went with independent, which removes me from the "primaries", but also removed me from all the non-stop text messages and phone calls begging for money to support a party that does little more than shrug non-committaly.
So, no? I'm from the US, I don't really get a choice in ISP, phone network, or political representative, but boy I sure do get to pick from a number of different cereals.
I am more active at the very local level, though, which seems to be the only place an individual can have impact.
Some good albums there!