It's 2008. You probably have contractors in 6 different time zones. Development in Russia, QA in India, home-sourced Customer Support in Utah, and an SEO link-builder in the Philippines. How are you communicating with your team?
Here are the tools that I love:
Google Talk - can't live without it. It's running 24x7 and stacked chats preserve my sanity. The translation bots are also uber-cool for communicating with any ESL (English as Second Language) colleagues.
Pidgin - so maybe you talk with people on Google Talk, Yahoo, AIM, ICQ, and Skype. Running out of system resources? Run Pidgin as your one-stop shop for chat clients.
Skype - can't beat it for Group chats or conference calls. I personally think VoIP quality is better on G-Talk for 1:1, but groups require Skype.
Yahoo Messenger - a nice full featured chat client. As with any chats for work, make sure to turn on archiving.
Bugzilla - a little difficult open-source-style UI, but very useful and powerful. Provisioned free with each oDesk account.
Basecamp - widely regarded as one of the best for task and project management.
Jira - also gets great feedback from project managers that utilize the tool.
Trac - useful and powerful open-source task management system. One of the few along with Basecamp and Jira that have risen to the top of the crowded project management software space.
Remember the Milk - for something a little different and lighter weight, check out Remember the Milk. You can share task lists and track status and priority of each items. Learn the hotkeys. Oh, did I mention it's free.
Google Docs - the days of emailing Word and Excel docs are dead. Use Google Docs for any simple documentation and get real-time online collaboration.
Expresso - uber-Excel-gurus may be disappointed with Google Spreadsheets, so for you guys, check out Expresso. It attempts to bring real-time online collaboration to a full-featured version of Excel, but it's still in beta (and it shows).
PBWiki - Simple, quick, efficient, free. Set up a wiki for any project.
Jot - More of a full-featured Wiki that we use internally all the time. They're not accepting new accounts right now since they've been acquired by Google, but look for it to be fully converted to a Google Wiki in the near future.
Subversion, SVN - another open-source gem. Any complicated software development will need a good source code repository. Provisioned free with each oDesk account.
MegaUpload - for sending that 1 gig file, email isn't gonna cut it. Check out MegaUpload, the most popular site I know of for large file-sharing.
You Send It - another large file-sharing site, I've heard good things.
CVSDude - pretty cool service and affordable monthly pricing for hosted SVN and Trac.
DevjaVu - impressive free offering for hosted SVN and Trac.
oDesk Share - live desktop screen-sharing. A must for some conference calls if you really need to get on the same page. oDesk Share is a lightweight app allowing the presenter to send a simple URL to the viewer (no download needed for the viewer).
Webex - same as oDesk Share, but the Rolls Royce of screen-sharing apps. Oh, and Rolls Royce's don't come cheap.
GoToMeeting - errr, same as oDesk Share, but let's call it an Acura.
Jing - Very cool application. Create a desktop screen capture image or video and upload. Most useful for quick video demos or descriptions.
Other Useful Ones
oDesk ShortURL - Need to share a 300 char parameterized URL? Turn it into a permanent short URL for emails or chat.
Earth Calendar - find out what holidays are going on throughout the world.
Logitech webcam for notebooks is my personal favorite - and I think everyone who gets one will be amazed at how much of a difference it makes in your communication. Reading emails and chats is impersonal, but add a webcam feed or portrait, and it changes the game.