As the internet can tend to decentralize collaborative teams, from a location perspective it is also important to note that some tools exist to help bring everyone together and get on the same page.
Google Docs helps you store, save, and collaborate on editing documents in real time. You can upload Microsoft-formatted works easily.
Dropbox helps you sync and share files . It is your thumb drive in the cloud. The free version starts at 2 GB of storage, but you can get more as you get other people to download and utilize the services (think online MLM with no costs; they reward you with additional storage). It also keeps previous versions of files as back ups.
Evernote creates digital bookmarks for you! It keeps everything you need in one handy place. It has a mobile app as well, so makes it very easy to use on quite a few devices.
Skype helps with conference calls, remote podcasting, chat, and filesharing. Also, you can buy U.S. numbers and use it for call forwarding when you are traveling abroad.
Basecamp enables you to file documents in a secure place. Using the platform, you can create teams working on different projects. You can allow different degrees of access per team member so certain sensitive information can be shown only to certain people. This tool is also good for client collaboration and makes projects management a breeze.
Which services do you use? Have I missed any? Mention them below in the comments.