Stores across Japan started taking orders on Thursday for the Roborior - a watermelon-sized eyeball on wheels that glows purple, blue and orange -  continuing the country's love affair with gadgets.

Roborior can function as interior decor, but also as a virtual guard dog that can sense break-ins using infrared sensors, notify homeowners by calling their cellular phones, and send the owner's cell phone videos from its digital camera.

It debuted in department stores this week, but supplies are limited. The robot is on display in a half-dozen shops, though many more are taking orders.

"We've had robots before that were just toys, but the Roborior can actually be put to practical use in the home," said Takako Sakata, a spokeswoman for the department store chain Takashimaya.

Such technology doesn't come cheaply. Takashimaya will sell the machines, developed by Japanese robot maker Tmsuk Co. Ltd. and electronics company Sanyo Electric Co. Ltd., for 280,000 yen ($2,600) each.

"We received a lot of inquiries after the demonstrations," Sakata said. "Our initial plan is to sell 2,000 robots."

Tmsuk has already produced a four-legged security robot called Banryu, which is about the size of a large dog and sells for 2 million yen ($18,000).