At the bottom of this post I am going to link you over to a post that has a list of tools that teams like RawVoice that are spread out all over the country can use to to work interactively online.

While the list is pretty good one thing that they missed is Virtual Phone Systems like GotVMail which allows a company to have a sophisticated PBX/Voicemail system.

I would love to hear from others on what kind of virtual collaboration tools they are using as well. www.readwriteweb.com