In Japan and most of Asia, documents require a seal. The Japanese word for these stamps is a typically "hanko" (判子) or inkan (印鑑), and they've been used for over a thousand years. People's names are carved onto them, and take the place of a signature when doing things like opening a bank account, getting married, or buying a car.
But now, in 2012, these traditional stamps are undergoing a radical change: Japanese nerdom.
These seals are called "itain", taking the Japanese "ita" (痛), which usually refers to pain, but more and more has a slang meaning: it is typically used for cars covered with nerd stickers. Though, in recent years, it can refer to anything covered in geek, including military hardware. Here, "in" is (印), which is the Japanese character for a sign or a mark.
These are not rubber stamps, but wood that's been hand carved by artisans.
The itain folks want to create seals that can be "registered" for bank or corporate use. Note that personal inkan are round, while businesses use a square seal.
In Japan, there are three basic kinds of seals: mitomein (認め印), which are unregistered seals for daily use, like stamping for a delivery; ginkoin (銀行印), which are used with bank accounts; and jitsuin (実印), which are used to do things like buy a home or a car or sign a will.
Why three different stamps? You could use your jitsuin for, well, everything, but it's generally thought best not to and to keep them all separate in case something happens. The jitsuin is the most important seal Japanese people (or foreigners like me!) carry, and it's usually kept under lock and key. Knowing how strict the Japanese government is about jitsuin (and what can be on them), these nerdy itain seals would not get the bureaucratic okay.
Itain are priced between ¥1,380 and ¥2,980 per seal, and you can send along the image you want engraved. The rub, however, is that e3paper is currently limiting orders to copyright-free characters in order to avoid lawsuit documents with, no doubt, legal stamps.
銀行印としても使える!? 萌えキャラはんこ「痛印」が人気 [Trendy]
痛印堂 [Official Site]