Highland Capital Partners has infused social news site digg with $28.7 million in fresh funding.

According to CEO Jay Adelson, the money will be used to improve infrastructure, expand internationally, add to the employee headcount ("check out our jobs page," he quipped) and roll pending programs into the execution stage.

"We have only completed about 15 percent of all the ideas that we have," Adelson told the Associated Press, adding that he hopes the financing will squash rumors that digg has been on the market.

"We want to be independent."

digg serves about 30 million unique users per month. Nearly half reside beyond the United States, said Adelson, who wants to "[make] digg more relevant to local tastes, including local languages" as early as 1Q09. By then, the work force is also expected to double to about 150, precipitating digg's plans to move to a larger San Francisco office and ramp up branding efforts.

Since the service launched four years ago, digg has raised about $40 million in venture capital. Revenue tripled over the past year, says Adelson, though the company has yet to turn a profit.