eBuddy is an easy-to-use web app that gives you a centralized online tool for chatting with friends from lots of different chat networks.
Anyone who has used an IM client will be familiar with eBuddy. You add usernames and passwords for the accounts you want to use and then click on the name of the friend you want to chat with to get talking - it's that simple. Just bear in mind that if you want to chat with friends from more than one network, you'll need a free eBuddy account.
The eBuddy layout is fun and young. The chat interface, which opens in a new window, is cute and skinnable, and there are basic options to toggle. There's a full range of notifications, animations and smileys, and some basic safety features (you can block users and prevent people who are not on your chat list from contacting you). That said, there's nothing very special about eBuddy, and besides freeing you from the need to download a multi-protocol client, there's not really much that stands out.
eBuddy supports lots of chat networks, but it's not very special.