Count it among the few genuinely useful iPhone/iPod touch applications that were spawned in the jailbreak scene then moved to to the Apple-sanctioned iPhone App Store. Also count it among the few applications that might soon be rejected by Apple, possibly at the behest of AT&T.
Orb is a newly released application that streams video from a Windows PC to the iPhone. It can deliver any video or audio that's stored on the the PC, YouTube content and, most important, live television if you have a TV tuner installed on your PC. This places Orb squarely in competition with Slingbox, which provides a similar level of functionality but does not yet have a native iPhone application. With the appropriate tuner, Orb delivers on the "live TV anywhere" promise brought to various other mobile phones by Slingbox.
Other applications, like telekensis for Mac OS X, allow Web-based streaming of video and audio content to the iPhone via a remote-control-like setup in which the iPhone displays a live picture of whatever is on the host Mac's screen. But Orb is the first application to deliver such functionality through the App Store with a streamlined interface that also allows access to live Internet television and cable/antenna television with a properly configured tuner.
Orb Networks says the application is "coming soon for Mac and Linux computers."
Unfortunately, Orb may become the latest victim of Apple and AT&T's rejection policies. Apple recently banned Cast Catcher, a streaming Internet radio application in the same vein as AOL Radio and Pandora (both of which have been available through the App Store almost since its inception), because the application "transfer(s) excessive volumes of data over the cellular network." Orb, with full video and audio streaming over 3G, ostensibly falls into the same category.