Enterprising developer Erica Sadun of TUAW fame has been reverse engineering Apple’s Airplay technology lately, and now she’s following up her successful Airplayer software for the Mac with AirFlick, a simple piece of Mac OS X software that streams any video or audio file to your second-generation Apple TV -- no iTunes required.

If you have been disappointed by how Apple has limited Airplay to their own iOS apps, you’re not alone. That’s why we’ve got to give mad props to Erica Sadun, a TUAW blogger and app developer who has been locked away tinkering with Airplay lately and found a way to extend some of its limited capability.

Sadun’s first effort was Airplayer, which allowed compatible iOS apps (including Videos on the iPad and the iPod app on iPhone/iPod touch, or YouTube on all three) to stream video to the Mac, thanks to a small OS X application she created.

Now Sadun is back with AirFlick, which streams most any video or audio file from your Mac to the second-generation Apple TV, no jailbreaking required. It also doesn’t require iTunes -- drag and drop a media file onto the AirFlick application and away you go. Here’s how it works.

1. First you’ll need to download AirFlick, a modest ad-supported 1MB alpha application that Sadun is offering free on her website for the rest of us to play with. The current version is 0.04 as of this writing.

2. Unzip the archive and drag the AirFlick program to your system’s Applications folder.

3. Double-click AirFlick to launch it. The app will immediately start seeking out any compatible devices to stream to, which includes other Macs running Airplayer as well as the second-generation black Apple TV. When it’s ready, you’ll see “Searching” change to the name of the first device found.

4. Select the device you want to receive your media from the choices listed; if you have only one, it will select it by default and you should see the name pop up like in the screenshot above.

5. Drag a video or audio file from anywhere (or type in a file path) and click the large Play button in the bottom right corner. Your media should start streaming to your selected device, although as you can see from Sadun’s how-to video, sometimes it doesn’t work on the first try. However, clicking the Menu button on your ATV remote and giving it another go will usually get things working as they should.

6. At this point, you can sit back and enjoy or click the Stop button if you’re finished.

AirFlick isn’t limited to just Apple TV-compatible files, either -- if you have a newer version of the free, open-source VLC installed, AirFlick will use it to transcode your video into something that the ATV can play. The only caveat is there will be a 30-second delay before the video starts to play, during which Sadun slyly notes is a good time to “Get a cup of coffee.”

Keep in mind that this is early alpha software and bugs can be expected -- we experienced one for ourselves while testing for this article after opening Airplayer on a secondary Mac and trying to refresh the available sources. Quitting the app and launching it again cleared things right up, and the problem didn’t occur a second time.

AirFlick and Airplayer show that there’s still a lot of untapped promise in Apple’s wireless Airplay technology, and thanks to developers like Erica Sadun, the best is likely yet to come.

Follow this article’s author, J.R. Bookwalter on Twitter

(Images and video courtesy of Erica Sadun and TUAW)