In the past decade, the reach of social network sites such as MySpace and Facebook has extended to a point where for many young people, participation is now mandatory for inclusion amongst peer groups. For some of these young people, large parts of their social lives have been played out on these sites. The shift from one site (MySpace) to another (Facebook) can also be understood as marking an important change in the way young people manage their digital trace. This shift corresponds with narratives in which participants signal their movement towards forms of online sociality that are concerned with their relationships with others on Facebook rather than the often introspective and performative forms of sociality emphasized on MySpace. This article examines elements of each site that participants point towards as contributing to their own shift - both in terms of their functionality and the broader social milieu in which the sites operate. More broadly, this article also considers the trace that is generated by participation on these sites (creating profiles, uploading images, commenting on pages and so on) as representing a key mechanism by which young people's transition narratives can be made accessible and visible amongst their network. This article draws on research from two linked small-scale qualitative studies conducted on the Gold Coast in Australia, the first with a group of 10 young people in 2007 and the second with 30 young people in 2009/2010.