Software for a Virtual Office?

Omega1045 asks: "I am working on a team that will soon be merging with another group of developers a thousand miles away, plus we already have remote people. Having been in this position at a previous job, I have used applications like IM, NetMeeting, email and a lot of phone calls to keep people in touch. Even with these things, there is still a lot missing in making sure we have good communication between members of the team. In my previous experience, we spent too much time on simple tasks like making sure everyone had the same copy of a file, the same update project schedule, etc. What tools would you recommend for a team working in Windows development? What experiences, good and bad, have you had with 'virtual office' applications. I am currently testing Groove Virtual Office which I spotted on Slashdot, earlier. Does Slashdot have recommendations for free software, or moderately priced commercial software, that might fig the bill?"