What are the ins and outs of switching political parties?

Far as I recall, you don't need to be a member of any party, ever, unless you want to vote in primaries, and even then you may not need to be (check your local election rules -- you're in California, yes?):
http://www.sos.ca.gov/elections/

I am in MA and I register as an independent. In MA, this allows me to vote in either party for primary elections. That is the big advantage I see. That and the fact that you get accosted by both parties as election day nears.

I am in Maine do the election laws differ here from California?

I like that Linkat, perhaps an independent is the way to go.

I just moved in Maine to a new residence close to my old address. So I have to register again. What do I write on the registration card? The election is tomorrow. I did not and don't plan to renew or pay this years dues to the republicans so I am in limbo. Do I need to pay the independent party to call myself an independent on the card?

I've never paid a fee to "belong" to a party. To register to vote there should be no fee. Can you call your local voter registeration to see what is involved for the election? ie can you be independent, but yet vote in the primaries? Some states will not let you vote in a primary if you are independent.

Some states do not ask for a party preference to vote.
However, voting in a primary is different.

There may be some residency requirements.

Call the Sec. of State's office. They should be able to guide you.