Google have been slowly invading lots of different markets over the past half decade, providing a free service which usually ends up being just as, if not more functional than the paid one it competes with, and it looks like they are about to do it again.

What's the market this time? Satnav. With the upcoming launch of Android 2.0, Google are rolling out "Google Maps Navigation" which is set to provide live, turn by turn directions to and from destinations of your choice. Automatic rerouting should you miss a turn or the like, will also be featured, as will photography from the really rather smart streetview.

Satnav giants TomTom and Garmin were hit heavily on the stock market after the announcement, with shares dropping 13 and 18 percent respectively; showing that there is genuine concern as to whether standalone units will be as viable with Google providing a free service which may end up being rolled out on more platforms than Android.

The only concern is to how it aquires map data; Google Maps does not have a large cache by default and downloads maps over the net as it goes, and worldwide mobile internet cover is still really not that great... so will it work? More as we know it.