http://www.gobenkyou.com
I figured I'd try to make something useful when I decided to pick up Ruby/Rails. It's a taggable database of Japanese learning resources.
If you have a few moments, check it out. Create an account, vote and comment on some sites, and please add your favorite links! Let me know what I can do to make the site more useful for you.
Books, dvds, software, etc. are okay, but to keep things consistent, please link to the Amazon.com's product page.
Or, if you're lazy, just post the link here with a short description.