Useful Networks announced the availability of its internationally popular mobile and Facebook integrated friend finder, sniff (Social Network Integrated Friend Finder), in the US. Already very popular in Scandinavia and the United Kingdom, sniff is now compatible with the Sprint Network in the U.S.  Unlike other friend finding services, sniff allows you to find your friends automatically and in real-time, rather than the last time they logged in to the service, by either sending a text message from their mobile phone or through the integrated Facebook application. No downloading or upfront fee is required.

Once consumers receive required permission from their friends, using sniff is as simple as sending an SMS text message. In return, sniff provides consumers with a detailed map view of their friends’ locations – making meeting up easier than ever before.

“There is inherent value in allowing your close friends and family to know where you are but only when you want them to,” said Useful Networks CEO, Brian Levin. “Friends can now ‘sniff’ each other out easily and quickly. That is, if they want to be found. You can easily become ‘invisible’ if you’d rather not be ‘sniffed out.’”

Another key aspect of sniff is the privacy controls built in to the application. The user is always in complete control of who can locate them and when. The sniff privacy model is based on the fundamental principles of user notice and consent. sniff also provides multiple confirmation notices to new users reminding them they have joined the sniff network so all users are aware of their status and permission levels.

“Privacy is the most important aspect of sniff,” said Levin. “With varying permission levels, sniff allows consumers to manage if, when and how their location information is shared with other parties. In addition, users have the ability to set up notifications via SMS of key events, such as being located or invited by another user to be part of the sniff network.”

sniff’s popularity is largely due to its ability to provide consistent coverage and an enhanced user experience across mobile carriers and handsets. “We wanted to make this service available to everyone, not just users with high-end phones who download applications,” added Levin. “If you can send a text message, you can sniff.”

Through the sniff Facebook application, consumers can easily invite, connect with and sniff their Facebook friends. Registration for sniff is free and takes just seconds by sending “sniff” to short code 76433 (sniff) from a Sprint device. “sniffing out” friends is charged at $0.25 on a “per sniff” basis and users are only charged if they receive a successful result. Billing is seamless, as sniff is the first Facebook application to apply premium charges to customers’ mobile bills. Standard text messaging rates apply.

Useful Networks intends to make sniff compatible with more major wireless carriers in the U.S. and available in Turkey, Canada and France in coming months.

In addition, Useful Networks is offering a sniff API for use by developers who want to incorporate friend finding functionality into existing social networking or community services.