WowAce

ChatThrottleLib is a small, embeddable library that helps AddOn authors keep outbound chat and addon communication from exceeding the output rate limit in WoW that otherwise causes players to disconnect from the server.

It also has a number of features that will help you make your addon communication run smoother!

See http://www.wowpedia.org/ChatThrottleLib for tech specs, API, SVN location, change log and more!