"nru" is an application from UK developers lastminute.com, designed like so many other recent mobile apps to location food, shopping, and entertainment deals around you. What makes nru (pronounced "near you") compelling is in part its platform, running as it does exclusively on the T-Mobile G1 powered by Google's Android mobile OS.
Because the G1 has a compass inside, nru presents its data as a sonar-like spinning map when held parallel to the ground, but presents a snazzy augmented reality overlay when tipped up towards the horizon. It's easier to grok when you can see it in motion; there's a video up above.
You can give it a literal whirl today if you're an Android user in the U.K., where it's available on the marketplace.
The merit of nru itself aside, it's clear that the addition of a compass to the G1 is its superlative feature. It's this year's accelerometer. I'd expect to see one in the next iPhone revision. By next year they'll be in digital picture frames and blenders, a nickel's worth of "Why not?" silicon telemetry.
From the examples of the augmented reality software like nru and Google's own Maps program, however, it's clear that we're a little ways away from the portable rendering power necessary to make these truly feel magical. The iPhone and G1's camera has horrendous refresh rates, akin to primitive digital cameras. Before we'll get truly amazing "looking glass" applications, our handsets will need either faster cameras or more optimized visual processing. We're really close, though. Can't be more than a couple of years out.