Managed to get free Sat Nav installed on my Samsung. There was no mention of navigation in the instructions on my phone. I'm on vodafone, but should work on all networks.
This is what I did (all legal by the way):
Activated Navigation in the settings on the phone, this just gives a navigation icon in the menu.
Inserted a micro SD card, as this is needed.
Went here: http://www.66.com/samsung/index.php?cid=UK&act=2&cat=2&scat=1
Download the software from the link above and followed instructions.
When you actually get to the online shop UK maps are free. Select this and checkout, maps will install.
This gives you fully working sat nav for foot or car.