Photo credit: Maxxyustas

1. MonkeyOn: Easily assign tasks to your team via email
2. DivShare: Store and share all of your files online, with 5GB of hosting space
3. Foonz: Create unlimited groups and call your personal number to create a group call
4. eTalkup: Track your web site's visitors and chat with them in real-time

1. MonkeyOn
   
   MonkeyOn is an online service that allows you to assign tasks to your team members via email. After you register, you can start assign tasks to your colleagues through a really simple interface: just type the email, description of the task, deadline and click send. You can then browse all the assigned tasks in your control panel, and manage them all. Free to use, registration required.
   http://monkeyon.com/





2. DivShare
   
   DivShare is a free online file storage that you can use to store and share your files online. It gives you 5 GB for free, in which you can upload all of your files, with no size-limit: you can upload images, videos, music and any type of document, that you can also get automatically converted into Flash format. Any file will then have a public URL that you can send to anyone to allow them to download that file. Free to use.
   http://www.divshare.com/





3. Foonz
   
   Foonz is a free service that anyone can use to have group calls. It allows you to create unlimited groups of people, with different numbers. When you start a group call, foonz instantly invites people to join your call by sending them a text message. Then, they simply dial the number in the text to automatically join your call. Foonz is completely free to use, with no limit in groups or people number.
   http://www.foonz.com/





4. eTalkup
   
   eTalkup is a free service that enables you to keep track of who's visiting your web site and to chat with them. You just have to register and embed a Java script inside your web site and you'll be ready to start talking with all of your visitors through a simple console that looks a like a normal instant messenger. eTalk up is free to use, but you can compare here the other versions. Registration needed.
   http://www.etalkup.com/