The forum set up for the Rails Recipes book has a section where readers can write their own Rails recipes. Some of them are pretty good and would have been good contenders for the book. Here are some of them:

• Create your own validates_abc_of validation - Show you how to create your own validation routines.
• Be notified when someone deploys your project's code - Good for multiple developer situations.
• Using a legacy database - Getting Rails to respect database decisions made pre-Rails
• HTML Whitelists: The Easy Way
• Quick and Easy Textfilters