Remember Bobsled, a service by T-Mobile that inexplicably let you make calls to your Facebook friends? Well it’s back and now it’s browser-based, allowing anyone with an iOS or Android phone or a browser to make calls for free. The service works in the U.S. and allows you to make free calls in North America and Puerto Rico. You can also call folks internationally using the same Facebook interface.

The service is free and you can access it and download apps at Bobsled.com. You can make web to mobile/landline calls from anywhere in the world, so this is a great way to skirt long distance fees.

In the end, this is T-Mobile’s way of making sure that data remains king. With manufacturers replacing voice calls and SMSes with their own proprietary systems – namely Google Voice and iMessage – carriers are wondering how to stay relevant. By buying and supporting these systems, they may be able to get a trickle of payments from satisfied users. It’s also an attempt to neuter the ever-popular Skype apps that also cannibalize voice and video calls.

As we’ve all learned from the dotcom days, if you build it, give it away for free, and wait for them to overwhelm your vastly overbuilt resources, they will probably maybe come. Here’s hoping.