Twitter love is showing no signs of abating in Japan. It's not just real live people "muttering" their 140-character thoughts, though. As much as a quarter of traffic on the microblogging site is thought to come from automated accounts, or "bots." Japanese Twitter bots are slightly different than English-language bots. While many of the most popular bots in English do something – remind you of your to-do list, say, or help you calculate a tip – a large portion of the most popular bots in Japan spout quotes from celebrities and anime programs.

And while Japanese engineers are working hard to create real-world robots that will fool us into thinking they're real, some of the artificial intelligence bots on Twitter have already succeeded. Last year, a Japanese blogger wrote about being surprised to discover that some of his Twitter friends were actually bots. There are scads of AI bots like Robot Secretary. Included in this group of advanced bots is the popular Shuumai, which "learns" speech by reading what people write and then tries to regurgitate it appropriately.

Who's who