Free music streaming service Last.fm plans to disable third-party applications that stream its content to mobile devices. It also intends to start charging a low monthly fee for the service outside the US, UK and Germany, IntoMobile reports.

Apparently, developers have been using undocumented APIs to hook into Last.fm in order to set up a mobile stream. The company will be shutting down those APIs, and making available a "public, documented streaming API." The new API will enable third-party clients, but will prevent mobile streaming.

Last.fm is reportedly cutting off the mobile access in order to comply with its licensing deals. Since the formerly independent site became a part of CBS last year, the whole complying-with-licenses thing should have been expected.

Guess the only folks who'll be listening to the service on a cell phone in the near future will be iPhone owners, since that's the only legit mobile client Last.fm offers.