WWW
Oh yeah, the country of advanced technology is still unable figure out the .htaccess file and how to redirect something.jp to www.something.jp. Prime examples are the websites of the Law Faculty of Kobe-U (www.law.kobe-u.ac.jp) and Space ALC - best online Japanese dictionary ever - (www.alc.co.jp). They don't work without the www...
This is only annoying because once I tried to look something up on ALC and it didn't dawn on me for quite a while that no the website is not down I just have to type the www part in as well.