Projectview shows projects in alphabetical order and sorted by priority. This allows a nice view of projects and todo items. It takes an option to grep across the todo.txt file so can be used to find by context or free form text etc.
Usage: todo.sh projectview testing
Projectrename allows you to rename projects across all the todo.txt file or just one or more lines.
Usage: todo.sh projectrename oldprocject newproject 1 3