Steven Lee, a senior product manager for Google who works on the company’s location products, said the search giant will release an application programming interface for its Latitude service — which lets you see your friends’ locations on a map — in the next few months.

Speaking on a panel at the SXSW conference in Austin today, he said the company will have a developer preview soon.

“We hope it will support and foster all sorts of applications,” he said. “Privacy will be very important to this as well. The user will choose for every application, whether they want developers to have access to that data.”

Since Google launched Latitude a year ago, developers have been looking for an API to be released. Other competitors in the space like Foursquare and Gowalla recently launched application programming interfaces, and more are expected from other location-based social networks over the next two months. Loopt CEO Sam Altman also said onstage that an API is forthcoming from his company.

“One of the APIs will be straightforward,” Google’s Lee explained. “It will be OAuth based and require permission per application. It will be relatively straightforward in terms of access.”

Lee defended the persistent location-sharing model that Latitude uses against the “check-in” use case that companies like Gowalla and Foursquare promote. He pointed to all sorts of interesting applications that could be built on the back of constant location awareness. Imagine an app that turns on the heat when it sees that you are driving home, he suggested.