Obsessed with golf? Yes, it's an actual affliction, according to the newest MasterCard campaign—an affliction that can be diagnosed by a new interactive golf page at Priceless.com. Designed by MRM Worldwide as a telethon hosted by CBS golf analyst David Feherty, with golf celebrities Arnold Palmer, Ben Crenshaw, Laura Diaz and John Barmon, Jr. manning the phones, the highly immersive experience uses a combination of Flash video and IVR (interactive voice response) technology to extend the campaign beyond the web. After dialing 1-888-ONE IRON and entering a special passcode flashing across the screen, visitors are patched through to one of the golf celebs, who asks a series of questions that determine your level of golf obsession. The hook? The "conversation" is actually synchronized with the video content on the site, so visitors can actually "see" their celeb quizzing them in real-time. (That's more synergy than you're likely to display on the greens.) After receiving their obsession score—based not just on the accuracy of your answers, but also on the speed of your responses—visitors can take a swing at some other groovy site content, including personalized emails from Palmer, text message tips from Diaz on how not to miss your tee times, and even a feature that lets you record Crenshaw's voice on your outgoing voicemail.