One great tool in this regard is TwitterFeed. It allows you to create "feeds", which will "listen" on RSS feeds and will then turn them into tweets. An obvious use case is to create a "listener" on your own block and make sure your followers learn when you publish a new blog entry.
A more sophisticated, integrated (and wwwwaaaayyyyy cooler) use case is to use NetNewsWire to read your RSS feeds/news/articles and use the integration with del.ico.us to bookmark what you read. You then go to TwitterFeed and create a listener on the RSS feed on your del.ico.us account and voila: everytime you are reading something and bookmark it with del.ico.us a tweet gets generated. Very elegant. I like it.
I also added a "My Del.ico.us" widget to my blog (on the right hand side), which means that my reading list will also get updated automatically.
Check it out. Let me know, if there are more better ways to integrate your online presence.