The First Letter script copies the first letter of the Key Field in any data table into a field named First Letter. This is useful for creating things like directories with single-letter subheadings. For detailed info on how to install and use this script, see the Single-Letter Headings blog post.
Scripts for InDesign
The Apply Object Styles script looks for paragraphs that are set in a certain paragraph style and that contain anchored text or picture boxes, and applies an object style to those boxes.