For some reason, Tokyo-based USB accessory maker Thanko has rolled out a slew of spy gadgets in the past weeks and months. About four weeks ago, Thanko gave us a spy pen that shoots video in HD, and today we are getting the Motion Sensor Spy Pen [JP]. The device looks like a regular ballpen, but it detects people moving in its vicinity and starts recording them on video automatically.

Unfortunately Thanko doesn’t specify the range of the motion sensor but says the pen stops recording automatically once it stops detecting movement for 10 seconds. The pen shoots video in AVI format and 736×480 resolution at 30fps. Alternatively, it can take pictures (JPEGs) in 1,280×960.

The pen weighs 30g, has 4GB of internal memory and a battery life of about 70 minutes. Needless to say, you can transfer your video or photo files to your computer via USB (Windows XP / Vista / 7 and Mac OS are supported).

Thanko is already selling the Motion Sensor Spy Pen on its Japanese website (price: $70). Ask Thanko partner and import/export specialist Geek Stuff 4 U if they can get one and ship it outside Japan if you’re interested.

Here’s a sample video (taken with the spy pen):