It seems that Research In Motion (RIM) just can't help adding new features to its BlackBerry line. It's barely six months since the 8800 was released and there's already a new model nipping at its heels. The 8820 offers the form factor and features of its predecessor but adds a couple of new extras - most notably Wi-Fi. Now, before you get all excited and start thinking of making next-to-nothing VoIP calls rather than paying over-the-odds mobile rates there's something to ...