I know there's been a few posts about Google Latitude, but back when it launched it seemed to be all vague and all, so here's a recent article which is actually more of a tutorial about using Google Latitude.
Latitude is actually part of Google Maps, you just need to download the right version of Google Maps [ google.com/latitude on your phone] .
It seems to work fine on my phone, i had no country-related issues [i.e. SA not being supported]
Another bitThe cool thing about Google Latitude is that there are really no fancy, expensive gadgets required. All you need is a mobile phone and you can build what’s essentially a GPS network of friends, without the need for GPS technology. Wondering whether your buddy Jim is still at work? Just log onto Google Latitude, or check Google Maps on your phone, and sure enough, Jim’s icon shows up on the map where he works. Did your best friend go missing after her date the other night? If she left her phone on, all of her friends can check out where she’s currently located.
This means that even if you don’t have your mobile phone with you, but you have access to the Internet, you can check out where all of your friends are at the moment, or update your own location on Latitude so that they know where you are. This whole concept takes the whole architecture and intent of Twitter and adds another entire level of graphical interactivity to it, with visual, real-time status updates for your friends.