A friend of mine recently told me about Feedburner's Socialize feature, where you can aggregate RSS feeds and post the links to Twitter automatically. This is quite a neat feature as Feedburner can also include some of your content in the tweet, create hashtags from the post categories and create inline hashtags from the categories and words in the title and post. Check out this feature by logging into your Feedburner account, selecting the feed you want to use, then go to the 'publicize' tab along the top then the 'socialize' tab along the side.

Here's how your tweet will appear: