Photo credit: Sachin Ghodke

1. Digsby: Combine multi-protocol IM, email and social networking into one application
2. TwitterShare: Share any file up to 10MB as a Twitter post
3. Wetpaint: Create free wikis and invite people to collaborate with you
4. SproutLiner: Create to-do lists and use to them to manage projects with your team

1. Digsby
   
   Digsby is a free web-based application that combines instant messaging, email and social networking. You can mix all of your contacts from MSN, Yahoo, AIM, ICQ, Gtalk and Jabber, into one buddy list and use email and social networking services like Facebook or MySpace from the same interface. You can have multiple conversations with people from different networks while you check your email. It also offers an embeddable widget for you to chat with your site's visitors. Free beta.
   http://www.digsby.com/





2. TwitterShare
   
   TwitterShare is both a web-based and a downloadable tool for Windows and Mac, that anyone can use to upload files and share them as regular Twitter messages. Whether you use the online or the software based TwitterShare, all you have to do is to drag&drop any file up to 10MB, provide your Twitter account credentials and click the arrow: your file will be uploaded and posted so that anyone can download it by following you on Twitter. Free.
   http://www.phoreo.com/twittershare/





3. Wetpaint
   
   Wetpaint is a free web-based service that allows you to create wiki pages for free. Just type a name, a URL and a description that best describes it, set the privacy settings, deciding who should be able to edit your pages and your wiki is ready. You and your team can then create text-pages, share any type of file, music, videos and images. Wetpaint is completely web-based and free to use.
   http://www.wetpaint.com/





4. SproutLiner
   
   SproutLiner is a free online to-do list manager service that you can use to organize your projects, but also to create and assign tasks to your team members. It uses drag&drop to let you organize and assign all of your on-going projects, set their priority. To start using it, just go on the page, and type a project name. It is free to use, no registration is needed.
   http://sproutliner.com/