Miranda IM pendrive version, software that allows you to log in to several instant communicators at the same time, does not need to be installed, just unzip and run.
Spreadtweet Utility that will turn your Twitter into an Excel spreadsheet.
Yoono Desktop Connect to all social networks and messengers in one place.
IMVU An innovative blend of instant communicator and life simulator.
IP Messenger Utility for network communication that, in addition to text, allows exchanging files and images.
sPortable Portable version of Skype that allows making audio and video calls, as well as sending instant messages, without the need for installation on Windows.
Ventrilo Software for group communication commonly used in games.