A free Skype application for iPhone will finally be available to download from the iTunes App Store sometime on Tuesday, CNET news has confirmed after sitting down with the lead engineer working on the iPhone Skype client.

“We got a chance to sit down with the application's principal engineer before the announcement was made at CTIA 2009, to see Skype for iPhone do its thing,” reads the report. Most of the features aren't too surprising, the site points out. However, Skype's aim right now is to maintain some consistency across its mobile applications.

According to those planning to release Skype for iPhone tomorrow, calls work only if you're in range of a Wi-Fi network, hence call quality will vary depending on the strength of wireless networks nearby. While chatting works over the cell phone network on the iPhone, calls don't. The app integrates with the user's address book, while iPod touch users will need Apple's earphones with a built-in mic to talk. Users can mute the line, go on hold, or put the call on speaker, while the My Info window includes a link to buy SkypeOut credit online.

Two iPhone-only features that make use of the phone's hardware attributes are mentioned in the report. Those are taking a photo from within Skype to serve as your avatar image, and pulling a picture in from the camera roll. While still a work in progress, there's also a feature supporting conference calls. However, users can only jump in on one, not create one. An update to the Skype client for iPhone should enable this feature in the future.

As for the functionality yet to be added, CNET mentions SMS, setting up a conference calling group, purchasing SkypeOut credit directly, the ability to field a second incoming Skype call, file transfers and native Skype voicemail. Still, readers should agree that free VoIP calls from an iPod touch is enough to get everyone talking, literally.