Photo credit: Rodolfo Clix

1. EkkoTV: Free service lets you have video conferences with other 2 people
2. Firefly: Install it on your server and chat with your website's visitors
3. TextFlow: Get documents reviewed by your colleagues and compare the corrections
4. Juslol: Log-in to your instant messengers accounts from one place

1. EkkoTV
   
   EkkoTV is a free Flash-based service that you can use to have video conferences online with other two people. Without even register, you can just enter your name and a new room will be created: then you just spread the URL and wait for your friends to join you. EkkoTV is completely web-based and free to use.
   http://www.ekko.tv/





2. Firefly
   
   Firefly is a free application that you can install on your server, and that enables you to chat with your visitors. After you install the software, people visiting your site, without installing any plug-in, can instantly start talking with your or between themselves via text-chat. Firefly is free to use, still in beta.
   http://www.firef.ly/





3. TextFlow
   
   TextFlow is a web-based service that allows you to compare multiple text documents in one single window. When you send off a document to your team and ask them to review it, instead of comparing all the version changes and then mix them up, you can just use TextFlow and choose which corrections are better, and get them inserted in the document. TextFlow is still in beta.
   http://www.textflow.com/





4. Juslol
   
   Juslol is a free web-based instant messenger that you can use to log-in to multiple IM networks from one windows. After you register, you can provide all of your credentials for Yahoo, MSN, AIM, ICQ and GTalk networks, so that you just have to remember one single password. You can then log-in and get all of your contacts mixed in one buddy list, and start chatting without downloading any software. Free.
   http://www.juslol.com/