Microsoft just showed off Vine, its new Facebook and Twitter-beater in one. It’s a dashboard widget for Windows PCs designed to show groups of friends who’s in the vicinity and what they’re up to. But there’s a more serious side than simply organising impromptu pub crawls.

Microsoft’s trialing its system with emergency services in tow, with its ultimate aim to help track where people are if there’s ever a natural disaster.

Its development was inspired by the confusion following Hurricane Katrina, and lets officials update local users in the event of an emergency. Of course, at the same time they can use it to organise weekly football matches. Or pub crawls. With updates on schedule changes automatically filtering to all involved.

Is it handy? Almost certainly. But Microsoft’s not alone in ploughing the location-awareness furrow. Twitter has the capacity to tag tweets with a geographic location, and new micro-blogging platforms such as AudioBoo integrate location data as a matter of course.

Even Apple is hopping aboard. The next version of its OS X operating system will include location awareness.

But Google could be about to squash the lot of them. Its Latitude technology will share your location with friends through a web browser on any computer, and it’s built into all new Android mobile phones too, as well as being prepped for the iPhone.

So where’s it all heading? My hunch is there’s a ton of money to be made from location-aware ads. Forget country-specific ad campaigns, with this technology advertisers could get down to street level. Searching for a restaurant on your phone? The nearest Cafe Rouge, Harvester or Bernie Inn could grab the space next to your search results, and pay mightily for the privilege.

Of course, sharing your location will never be compulsory, but with so many tech firms weaving it into their products it’ll soon become standard practice, and if you’re not visible on the map, people will start to wonder: what exactly are you up to? Big Brother isn’t just watching, he’s talking behind your back and selling you to the highest bidder.