Lifehacker has good advice about how homeworkers working in a team from a 'placeless office' can keep in touch at Essential tools for the placeless office. As they say: "If your team is distributed across vast distances like we are, you need to set up shop not with Aeron chairs and cubicle walls but with the right collaboration tools."
Their suggestions include:
* Campfire (for group chat meetings) rather than instant messaging
* MediaWiki (for internal knowledgebase e.g. style guides, research, brainstorming)
* Gmail (for email)
* Google calendar (for scheduling)
but there are many more so it's worth reading the whole piece as this is surely the way that groups of home office workers will start to work together increasingly frequently.