Information Retrieval (IR) is typically an individual pursuit where an individual searcher will engage with a search system, working alone, until their information need is satisfied. Yet in the real world there are many scenarios, both work-related and related to leisure, entertainment or hobbies, where we want to search as part of a team, maybe even a group of only two people. Collaborative Information Retrieval (CIR) refers to technologies which support collaboration in the retrieval process.  In this presentation we will present both synchronous and asynchronous CIR as well as covering remote and co-located search, and the various combinations of these. In our work we are particularly interested in synchronous collaborative IR (SCIR) where a group of users work collectively to address some shared information need. We describe two systems we have developed to demonstrate SCIR, one on a gesture-based tabletop computer and the other on touch-based mobile devices (iPODs). We believe SCIR to be an important kind of social search even though the tools to support this are neither widespread nor reliable and are limited by the technology we currently use. Despite this we expect the importance of SCIR to grow as a consequential fallout of growth in social networks and the trend towards social networks now acting as platforms for applications, like search.