[NTREEG]

More tips:

When you enter someone's home, say "ojamashimasu" (sorry for interrupting you). As you're leaving say "ojamashimashita" (sorry for having interrupted you).

At some restaurants / bars you'll need to take off your shoes. Basically if there's a raised platform that you have to step up to, it's very likely you're supposed to remove your shoes. Last week I got yelled at for wearing shoes into a fitting room at a clothing store. I should have known better when I saw the platform but I wasn't thinking about my shoes.

Never attach the title "-san" to your own name. Definitely attach the "-san" title to everyone else's name unless you know them extremely well (i.e. your girlfriend / boyfriend).

If you're spending the night at a family's home, they'll often offer you the privilege of being the first to bathe. I didn't understand this the first time it was offered to me and I committed a faux-pas by refusing the first bath (as I prefer to shower in the morning). Some Japanese house holds reuse the bath water for the whole family. If this is the case, the bath tub is not for bathing (i.e. soaping up). It's for relaxing in after you've already soaped up and rinsed off in the shower outside of the tub.

If you're having dinner at a restaurant and someone treat's you (pays the bill), say "gochisousama deshita" to the person that paid the bill.

If you're out drinking with a buddy and you're sharing a bottle of beer, fill his glass for him. They'll fill yours for you.

If someone cooks something for you, say "oishii" after taking a bite. It means "delicious". Say it even if it's not really oishii so as not to hurt their feelings.

If you smoke, be careful where you smoke. Some streets forbid smoking even outdoors.

If you're a guy and you're taking a train, be careful that you're not stepping into a "women only" car. There's usually a pink sign somewhere letting you know if it's for women only.

At many hotels, you're supposed to leave your room key at the front desk before going out for the day (quite different from the U.S.). Some business hotels have rules against bringing guests up to visit your room, even if it's just for a short while. BTW, if you enter your hotel room and can't figure out why the lights won't turn on...you have to stick your room key into a special slot before it'll turn on the electricity.

The Japanese have different trash cans for burnable and non burnable garbage. It's a forgivable mistake for non-Japanese to use the wrong bin, but make an effort to find the right one when you throw something away (at restaurants, convenient stores, etc). Recyclable plastic drink bottles are called "PET bottles" and they usually have their own trash can.