Photo credit: Sebastian Kaulitzki

1. Pidgin: Multi-protocol instant messenger lets you chat with people on different IM networks
2. Scribd: Upload documents online, convert them between various formats and embed them on your website
3. Goplan: Online project management tool allows you to set up tasks and collaborate with your team
4. SharedCopy: Add notes and highlights on a webpage and share it through a URL

1. Pidgin
   
   
   
   Pidgin is a multi-protocol instant messenger that allows you to chat with people on different IM networks: it supports AIM, ICQ, Jabber, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, Novell GroupWise Messenger, QQ, Lotus Sametime, SILC, SIMPLE, and Zephyr. Its key features include file transfers, tabbed conversations and away messages. Free beta available for Windows and Linux.
   
   http://www.pidgin.im/





2. Scribd
   
   Scribd is a website for uploading and sharing documents online. After you upload a file(.doc, .pdf, .txt, .ppt, .xls, .ps, .lit), you can convert it between various formats, get a URL to share your file with other people or embed it on your blog or website. Free to use.
   http://www.scribd.com/





3. Goplan
   
   Goplan is an online project management solution that allows teams and individuals to collaborate online. Its main features include real-time chat, online calendar and task manager. The free version has 5 MB of file storage. Other versions here.
   http://www.goplan.info/





4. SharedCopy
   
   SharedCopy is a web site that lets you share and mark up web pages. When you want to share a page, you just click a button on your toolbar, add text notes and highlights to the page and, when done, you are provided with a URL that you can share with anyone. Free.
   http://sharedcopy.com/