Arrangements and procedures for arranging peer-to-peer communications sessions between applications are described. In one implementation, a first application executing at a first device utilizes online presence information of an instant messaging service to select a second application with which to engage in the peer-to-peer session. The second application is associated with a second device and registered with the instant messaging service as being peer-to-peer session invite capable. The first application arranges the peer-to-peer session via components of the instant messaging service. The arranged peer-to-peer session is functionally independent of the instant messaging service.