Tweet Blender is a plugin for BuddyPress that is tag-aware and has support for multiple authors, lists, hashtags, and keywords all blended together. The plugin can show tweets from just one user or a list of users (as all other Twitter plugins do); however, it can also show tweets for a topic which you can define via Twitter hashtag or keyword. But there is more! It can also show tweets for multiple authors AND multiple lists AND multiple keywords AND multiple hashtags all blended together into a single stream.
Version 3 added a new widget that automatically shows tweets relevant to your blog post by taking post’s tags and using them as keywords for Twitter search.
Download, Info and extensive feature list at: