CachedTwit

A small lightweight class for loading in Twitter posts from any account via the RSS API and caching them to your local system at an interval you provide that is triggered when the tweets are called for. This script will work to 1-20 of the most current tweets. If you need more of that or the ability to pull older/specific tweets, you should look into a full Twitter API plugin. They will be a little more complex, but should handle that.