SlingMedia will be setting up shop at a San Francisco Starbucks this afternoon to demo a "jail broken" version of its SlingPlayer Mobile for the iPhone.

Apple plans to launch its App Store in June, but some developers have naturally found a way to install software on iPhones before the store's launch. Among those working with these "jail broken" iPhones is Sling, which currently has a proof of concept version running on iPhones, according to a spokesman.

In conjunction with WWDC, Sling will show off its SlingPlayer Mobile for iPhone at the 120 4th St. Starbucks in San Francisco between 10am and 4pm PST today to anyone who wants to see it.

Sling worked with the "jail broken" version in order to "characterize the performance of the platform and ensure that we could deliver a high quality customer experience on the iPhone & iPod Touch platforms," the spokesman said.

"We do not intend to make this available to customers, it is a proof of concept," he continued. "We are looking forward to the iPhone SDK becoming publicly available this week and fully intend to develop SlingPlayer Mobile using the SDK and are looking forward to selling it through the iTunes store."