I'm not the leading expert on virtual collaboration, but I did complete my Undergrad and am completing my Masters degree virtually. In that time I've worked on numerous virtual teams. Here are a few guidelines I've learned on how to form successful virtual teams.
Guideline 1 - Pick your teammates wisely!
If you have the option to choose your teammates, try to find people that communicate the same ways you do. I typically try to find teammates that like to communicate via some kind of instant messenger. This gives us the ability to have synchronous conversations.
Also, find teammates that have the same work collaboration style. Some people like to work solo and then bring their work to the group. Others like to work collaboratively. It's really hard to mix the two without running into conflict at some point.
Guideline 2 - Immediately create a team charter!
A good team charter will set the standards for your team. They describe communication strategies; they set critical success factors; they describe what you will do as a team if you face conflict; among other things.
Guideline 3 - Determine what software you will use to communicate!
I have yet to find a software tool that does everything. It's important that virtual teams are operating on the same software to avoid duplicating work. I like to use Yahoo IM for chat, Google Docs for virtual collaboration (within a document), bubbl for mind mapping, email for asynchronous updates, getting everyone on the same page, and sending out meeting minutes, and skype for conference calls. It might also be important to have some kind of screen sharing software.
Guideline 4 - Someone needs to be in charge (Project Manager)!
Usually someone will step up, but when no one takes charge, meetings tend to be less productive.
Guideline 5 - Stay in constant contact!
Once the team has begun work, staying in constant contact will help the team go through the standard team forming phases (forming, storming, norming) faster. It also helps with brainstorming and improves collaboration.
I'm sure there are many more guidelines out there on the subject, but I always try to follow these guidelines when I begin, or join a virtual team.