)*
The rules of virtual collaboration differ whether one is collaborating within the highly-controlled organizational environment, as an individual on the Internet, or as an organization trying to engage in two-way conversations with groups and individuals beyond the edge.
Each segment has its own rules of success, and different tools and techniques apply. Tools successful in one segment will frustrate and fail you when applied to other segments.
Collaboration within the organization benefits from high information throughput (a) - face to face contact, body language, shared history, shared symbols, and high trust.
The organization can afford to invest into a set of complicated tools, and compensate for complexity through employee training. Everyone has the same tools, peer support is easy as just asking a colleague at the next desk. Networks are fast and connected to file and intranet servers, it's easy to send large files and video across the local network and have the recipient easily open and use them. At least in theory.
Tools successful in this segment leverage the fast local network and are focused on integration with uniform tools installed on every desktop (Sharepoint, Lotus Notes).
The edge is both real and virtual. It's the wall of your office, keeping outsiders from getting in and stopping your voice spreading beyond it. It is also the rules and the firewall your IT people put in, protecting you from bad things getting in, and preventing you from putting things out beyond your office network.
The edge is a difference between two pages of email that barely begin to explain something to someone you never met in person, something you could say in two words to your co-worker and be understood. The information throughput sharply falls beyond the edge (b).
Yet, to engage in a conversation with the Outside, you must cross the edge of your organization's network.
Once you reach beyond the edge, follow these principles of success.
The Outside is a low-trust environment; different rules apply here. On the Internet, nobody knows you're a dog; only the simplest interactions work in the realm or super low throughput among individuals, and those are usually of transactional nature. In the infinite and hostile world of the Internet-at-large everyone stands alone.
These are the people you want to reach: your constituencies, your donors, the experts, the people you are helping; the 1.5+ billion Internet users. One can safely assume only one thing about people on the Outside: everyone has an email address.
Tools successful in this segment are transactional (eBay) and rely on large critical mass of individuals working in their self-interest (flickr, del.icio.us).
* Reach beyond the edge. 
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