My workplace will soon be shifting to the concept of 'activity based working', which moves from the idea of IT teams, BA teams, PM teams, etc to project-based work where people from across all facets of IT and the business involved on a project sit and work together. As a result, you wouldn't be sitting with your normal team colleagues on a day-to-day basis and sharing knowledge in that sort of organic way with the rest of your dev team won't really be happening.
What ways would you recommend to help preserve that team collaboration and knowledge sharing when people will not physically be co-existing alongside their teammates any longer? Not to mention preserving that 'geek spirit' (bad term perhaps) that sees devs encouraging and coaching each other to find better designs and solutions.
I've already thought about online collaboration tools such as Trello or Mingle, plus wikis or software such as Confluence to help collaboration and discussion. But I'd be interested to hear peoples opinions on what else could be done, or their own experiences with this approach to day-to-day work.