GOING TO JAPAN: Serious Questions

I’ve already posed these questions to a few people, but I figure I’ll put them out in the open to get a wide variety of opinions.

With my apartment paid for and my visa secured, I am 100% ready to take on glorious 日本. However, I can’t just go in there without any preparation–I have to be ready. As such, I have a couple of questions for people who have been to The Other Country before, and hopefully they can help me out.

1: Money- What do you do about money in Japan? I’ve read that most places won’t take foreign ATM cards, with the exception of 7/11 and post offices. So, what do you guys do? Get an account at a bank with international branches? Stuff your suitcase full of traveler’s checks? Just hit up the 7/11s and post offices because they’re ever so plentiful? What do you do?

2: Cellphones- I know the deal with prepaid phones in Japan–if you’re not Japanese, you need an alien registration card (I’m going to need one of these anyways), or you can go to a place that accepts US passports, and uses the address of your hotel for validation. So, my question is, what places have the best deals?

That’s about it, actually. I guess it’s not all that serious, but it’d be nice to get some Hot Tipz.