Late in 2009, Google released Google Maps Navigation for Android devices, which effectively brought free turn-by-turn navigation to every Android owner in the U.S.
Now, Google Maps Navigation comes to the UK and Ireland, and it works on smartphones running Android 1.6 and later. Voice commands and voice search, street view, traffic warnings, POIs and step-by-step directions are all there, so once again, it makes less and less sense to actually pay for GPS navigation software when you can get all of that for free.