Digsby is a pretty cool application that lets you do you chat with all your friends no matter which client they are on. Also the application provides an email notification tool that alerts of new mails(all networks) and provides simple functions like delete and mark as spam. And, there is a social networking tool that informs of new messages and your friends activities that are going on in the social networking Websites such as FaceBook, MySpace and Twitter.
[Download: Digsby]