Virtual offices, where employees and co-workers can be located in any corner of the world, have become a reality. More and more businesses are keen on exploring the concept of “virtual office” because they save on office rentals, employee commuting costs and host of other “unnecessary” expenses.

While members of a virtual team do not meet face to face very often, they do frequently interact online for discussions, brain-storming and training sessions to ensure that everyone is on the same page.Here we look at some extremely useful online tools and web services to help your virtual teams connect and collaborate with each other and with clients.

Email and Calendar: If you are running a virtual office, you need Google Apps. Period. This powerful suite offers email (Gmail), calendar (Google Calendar) and web-based Office suite (Google Docs) for each of your employees with plenty of storage space.

Instant Messaging: While Google Apps also provides a lightweight IM client called Google Talk, Skype is recommended because it also supports group chats and video conferencing in addition to text and audio chats.Another useful feature of Skype is SkypeCasts where you can host voice conference calls with dozens of participants. The host can easily moderate discussions in Skypecasts. Cost: $0.

Online File Storage: When you have a virtual team, it is important to maintain a repository of documents (and other files) at some central location that can be accessed by other members 24x7. This could include client proposal templates, PDFs, software installers, photographs, video clips and more.

Box.net provides a very simple explorer like interface for storing your files on the internet categorized using tags and folders. The free version of Box.net offers 1 GB of storage space. Other popular player in the online storage space businesses are XDrive (AOL), Adobe Share, Office Live Workspace (Microsoft) and the upcoming Google Drive.

Telephone Calls: Though it is possible to make PC-to-PC phone calls using Skype or Yahoo! Messenger for free, JAJAH is a more appropriate and cost-feasible solution if you want make long-distance or international phone calls.JAJAH uses VoIP to connect traditional phones (landline or mobile) and hence the calls are relatively cheaper than what telecom companies would charge for the same call.

Technical Support: While big companies have proper IT staff to fix technical issues, virtual offices can consider using CrossLoop, a remote desktop sharing solution. When you face a problem with your computer, any expert in the team can take control of your machine using CrossLoop and fix the issue for you. Price: $0.

Screen Sharing: Microsoft SharedView is a free screen sharing application that allows upto 15 virtual team members to connect and collaborate. They can share their desktop screens, work together on the same document (and track changes) and transfer files.

SharedView is a good choice if you have to deliver a lecture or training session online to a large group of participants.

The other option for web meeting is Adobe Brio that also offers a whiteboard, some annotation tools, voice and video chat but Brio (the free version) only supports a maximum of three participants per session.

Setup Network Folders: Leaf Networks provide a simple solution for you to share files and folders on your computer with other team members. It’s like a virtual LAN - you designate the files / folders that are to be shared and then invite others to connect to your computer. And not just files, Leaf can also be used for sharing network drives and printers - that means you can send print jobs even remotely.

Discuss Real Designs: If your work involves discussing designs, layout and prototypes with teammates and remote clients for approvals, ConceptShare is all that you need.

It’s like the designers and clients sitting on a virtual table with the project designs rolled out before them – they can mark things that need to improved, add comments and more. The basic version of ConceptShare is free.

Other than these “work related” tools, you can also consider using Wikis (Wetpaint or the upcoming Jotspot) for teammates to connect with each other for fun and non-work related activities.Start Pages (like Netvibes or PageFlakes) can be used as virtual notice boards where one can read all the important announcements, upcoming events, TO DO lists, news, blog buzz and more.

And most of these tools can be accessed from the web browser or even your mobile phone. Also read our Google Apps review.