The present invention provides methods of inter-technology handoff of a multi-mode mobile unit in a packet-switched communication system. One embodiment of the method includes establishing a call from a first application layer client in the first mobile unit using a first wireless communication link that operates according to a first wireless access technology. The method also includes sending, in response to detecting changing conditions of the first wireless communication link, a request to form a conference call including the first application layer client and inviting a second application layer client in the first mobile unit to join the conference call. The second application layer client uses a second wireless communication link that operates according to a second wireless access technology. The method further includes handing off the call from the first application layer client to the second application layer client.