The coming generation of mobile phones will enable objects from enterprise systems to be distributed across a range of devices of different scales. This object mobility will provide for applications that can take advantage of device-local data and processes to support rich client interaction. However, such mobilised applications bring with them new challenges for the software architect. Distributed objects running on telephones or other small mobile devices will have to work within a number of key constraints, such as limitations on memory and available APIs, and the need to maintain data integrity. This paper focuses on the issues of distributed architectures where objects are able to run on mobile devices but must be universally synchronised. Specifically, it looks at how aspects of current and developing Java APIs can support architectures that synchronise mobilised objects.