This tiny mouse is designed for PowerBooks and iBooks with built-in Bluetooth - or any OS X Jaguar or later Mac with a Bluetooth adaptor. Macally has decided to take a different approach to many other peripheral manufacturers and make a notebook mouse with a charging cradle.
The cradle charges up the mouse via a USB cable, so you could plug it into your Mac at home and charge while not in use. It uses two rechargeable AAA batteries, which are supplied. The underside of the rodent also incorporates a power switch so you can conserve power. The cradle isn't the finest build quality we've seen though - it feels clumsy when detaching the mouse from the cradle, and this process requires some jiggling around with the button on the cradle's base.
Pairing the mouse with your Mac is a simple task - select 'Set up Bluetooth Device' from your Bluetooth menu and follow the instructions given. The functions of the left, right and scrollwheel buttons can be changed, while they can also be assigned functions within Exposé.
There's one major problem with the BT-Micro. It's not as nice to use as its competitors. Microsoft's notebook mice and Logitech's new V400 range may not have Bluetooth, but both have wireless capability and laser mouse technology. This is more precise than optical, especially on previously unchartered mousing surfaces such as a fold-down table on a train.
But the main advantage of these mice is that they're slightly longer in body and far more comfortable to use than the BTMicro, which you can't ever feel truly comfortable with. Despite the need to buy batteries every six months or so, they do have a slight price premium over the BT-Micro too, but it's not much.
If you're that concerned about having a Bluetooth mouse for your PowerBook, go for the BT-Micro. However, more usable mice are to be found elsewhere. Dan Grabham