What if one day you decided that you'd like to leave LinkedIn or Facebook, wouldn't it be nice to have your contacts safely stored on your hard drive? And what if you'd like to find out if your contacts on LinkedIn are also on Facebook?

Enter Open Xchange. This Web service can be set up to bring in all your contacts from Gmail, LinkedIn and Facebook, and you can then publish all of this information on to a Web site or download it to a file for you to have control of your data.

You can purchase a license if you don't want to use it on the Internet. It has plug-ins for Outlook, iPhone apps, and it allows the import and export of calendar items.

Get more info at http://www.open-xchange.com.