Bike riders are a pretty independent breed, although even the best sometimes need a helping hand, which is where RWC's Bluetooth-equipped waterproof sat-nav comes in.

For ¥69,800 (£292) our two-wheeled friends in Japan get the nifty-looking RM-A4000 GPS unit to clip onto their handlebars. It measures 115 x 30 x 80mm, weighs 260g and is even aerodynamically curved to reduce wind resistance.

Windows CE on the road

Map and address data are stored on a supplied SD card, while there's 64MB of internal ROM for a copy of Windows CE 5.0, along with the various applications needed, and the same amount of SDRAM for the system to work with. As with all modern sat-nav units, the usual audio and video file formats can be played back.

Perhaps the most innovative feature of the device is a Bluetooth link for getting the spoken route-guidance prompts to the rider's ears. RWC thoughtfully supplies an in-helmet Bluetooth headset, although there's no reason not to use an existing favourite.

Naturally, IPX3 waterproofing ensures the innards of the A4000 stay dry although the absence of cigarette lighters on most motorbikes means riders will need to manage the five-hour battery life carefully. Recharging is a simple matter of finding a car with a lighter socket or using the included AC adapter.