If you happen to see people making strange faces at their iPhones in the next few days, blame Skype.
The Internet telephone service introduced video chatting on Thursday for iPhone users who want to not just hear who they call, but also see them. The new feature comes in the latest version of Skype's iPhone app, available in Apple's App Store.
Users can make free Skype-to-Skype video calls over AT&T's 3G network and on Wi-Fi. Android phones are not yet compatible.
Video chatting is already popular among people who use Skype on their computers, accounting for 40 percent of all Skype minutes during the first half of this year. However, Skype's mobile phone users have been unable to make and receive video calls until now.
"We think it's really important because it will make it easier for people to share moments," said Rick Osterloh, vice president of products for Skype.
Video quality is good as long as the network connection is strong, he said. If the network is slow, users are better off making an audio-only call, he advised.
A gauge in Skype's window indicates whether a video call is recommended based on the network speed.
Other services also offer mobile video calls including Apple's FaceTime, Fring and Tango. FaceTime is not sanctioned for use over AT&T's network.
Skype, which has 124 million active users, most of whom use the service on personal computers, is trying to stay relevant in an era when more calls are being made on mobile phones. Finding new sources of revenue is a top priority for Tony Bates, the company's new chief executive.
Adding mobile video chat does not directly make money for Skype other than to potentially entice more users to make paid calls. Calls are free between Skype users, while users must pay to call landline phones and mobile phones that don't have Skype.
Last week, Skype suffered an embarrassing outage over two days.
Skype's new app is compatible with recent iPhones and iPod Touches. Recent iPads can receive video calls, but not make them.