Twitter feeds and Facebook are replacing web browsing and email for many of us, but seasoned social networkers know the revolution is only just beginning. In fact, the next phase may already be underway with Knocking Live Video and Ustream Live Broadcaster, two video-streaming tools that put the power to share live video with friends, family, and followers in the palms of your iPhone-clutching hands. Both apps offer fun features, impressive tech, and our favorite price tag: free! But which one should you use?

Knocking Live, the first of the pair to hit iTunes, received as much buzz for its history as its functionality. As the campfire tale goes, it was originally rejected by Apple, but a plea from the developers directly to the mock turtleneck–wearing big man himself got it reevaluated and approved overnight. While this publicity gave the little app a big boost, it also ensured it was downloaded in droves--resulting in overloaded servers and a buggy debut. After that blessed-by-Jobs hype died down, we gave Knocking Live a spin and came away mostly impressed.

Knock, knock. Who's there? Random video of me doing stuff, thanks to Knocking Live.

This intuitive app is simple to use, but it’s aimed more toward folks looking to share something cool with a friend, rather than the hardcore social-networking crowd. It’s not about broadcasting to the masses, but “knocking” on a fellow iPhone owner’s device to share a moment as it happens (yes, your phone makes a knocking noise to call attention to an incoming video). This could mean a mom streaming her baby’s first steps to dad at work, or, more likely, a crazy cat owner sharing a video of Whiskers chasing his tail with another feline-loving friend. (Okay, yes, that last one actually describes our test.) And despite occasional glitchiness--lengthy launch times, sporadic crashes--it worked like a charm. We streamed some kitty vids to a friend, who first had to download the app to receive our “knocks,” then had him stream some back to us. The magic happens over 3G or Wi-Fi, but disappointingly, Knocking Live doesn’t provide audio or video recording, though the developer has promised these necessities in future updates.

While Knocking Live is a neat little app for sharing precious (and not so precious moments) with friends, its limitations mean it won’t exactly start your viral video revolution. For that, you’ll want to check out Ustream Live Broadcaster. While more options and modes make it a bit more complex to set up and navigate, social-networking geeks will have no problem running it. In fact, with the ability to upload to YouTube, Twitter, and Facebook, your video can be everywhere you want it to be in a matter of minutes. Best of all, Ustream also boasts the benefit of working as a straight-up video recorder, so 3G owners--who don’t have this ability built into their devices--can use it to shoot video even if they’re not interested in streaming. As with Knocking Live, Ustream runs over 3G or Wi-Fi. But unlike the first kid on the block, it delivers audio, allows you to save your recordings, and even runs “yes/no” polls during your feeds. Those are huge advantages.

Ustream lets you stream and save video even on the no-video-recording iPhone 3G.

So now it’s time to choose. Knocking Live effectively gets the job done if you’re looking to connect with individual friends, but if you’re thinking Twitter and can handle a bit more complexity in the app, Ustream should be your go-to video tool.

Knocking Live Video 1.0
COMPANY: Pointy Heads
CONTACT: www.knockinglive.com
PRICE: Free
REQUIREMENTS: iPhone 3G or 3GS (with iPhone 3.1 OS), touch (2nd gen or later)
Simple to use. Quick friend-to-friend streaming. Works with 3G.
No audio. Occasionally buggy. Can't save recordings.

Ustream Live Broadcaster 1.1
COMPANY: Ustream
CONTACT: www.ustream.tv
PRICE: Free
REQUIREMENTS: iPhone 3G or 3GS (with iPhone 3.1 OS)
Uploads to social networks. Works as a video recorder, even on a 3G. Streams audio with video.
Comparatively complex setup and navigation.