FringFring, which started out offering a VoIP client for mobile phones has added the ability to make and receive video calls from mobile phones, letting you see your friends as you talk to them — for free.

As with the VoIP client, you have to be a Fring user, or “fringster,” as CEO Avi Schechter calls them, to download the video client. Fringsters can then talk to friends outside of Fring via various services, including Skype, Twitter, Facebook, last.fm, Google Talk, and AIM through a combined friend list. Fring makes money through banner ads and other advertising mechanisms. Schechter says the ads are not very intrusive. Fringsters can use the mobile client to live chat, update profiles, and share files.

“This is a natural extension of what people are doing on the mobile internet,” said Schechter. “Until now, lots of communication has been traditional, whether SMS or voice calls, and we believe bringing Internet communications to mobile will benefit mobile users with new experiences.”

Fringsters span about 200 countries, are 20-30 years old on average, and skew mostly male, as with most VoIP services. But Schechter says this profile is changing quickly. The majority of users have come from Western Europe so far, but there are more and more US users downloading the service, especially now that it is on the iPhone.

While you might think operators would feel threatened by such a service, Schechter says they are not because they are interested in pushing higher-end smartphone devices into the market from which they get a higher ARPU. They’re also interested in making mobile central to users’ lives. Most mobile operators in Europe and Asia have some kind of video calling experience available to users, but Fring enables users to combine their AIM buddy list or Skype friends or Twitter followers with this mobile video calling capability without being tied to a computer as you are with Skype’s video calling, for example.

Seesmic focused on video conversations when it launched in 2008, but it has now shifted towards being a Twitter client.

Fring has also been working closely with phone manufacturers, including Nokia, whose Ovi store they participate in, and operators, including O2 in Slovakia and Mobilkom in Austria.

Although Fring won’t disclose the total number of downloads of their VoIP application, Schechter said they have half a million activations per month on smartphones only, and the average user uses the service for 4 hours per day. (They define an activation as a user who downloads the service to a mobile phone for the first time.)

Fring video calls are currently available on Nokia X6, N97 mini, N97, 5800, N95 8G and N95 devices as well as Symbian, Android, Windows Mobile, J2ME and Linux devices, and the company plans to launch video calling on the iPhone (the VoIP app is already available on the iPhone, but it does not yet include video). Schechter said they’d like to further expand the service but are focusing on higher-end handsets in an effort to ensure users the full experience of video.

Fring is headquartered in Israel but has offices in London and Washington DC. The company completed its third round of financing in April of this year. Its main shareholders are two Israel-based funds, Veritas Venture Partners and Pitango Venture Capital, Boston-based Bridge Venture Partners and South African fund VenFin Limited, as well as private investor Yossi Vardi, the founding investor of ICQ.

The company is focused on carrying its existing feature set to additional platforms and mobile phones and devices but also has a somewhat ambitious plan of launching new clients or services as frequently as monthly, according to Schechter.

I’m an iPhone user, so I wasn’t able to test the new service out on my phone, but from the company’s demo (see video below), it looks like the service works well, even if the quality isn’t quite stellar.