Modules providing Tokens

Token (http://drupal.org/project/token)
Provides a shared API for replacement of textual placeholders with actual data.(This functionality is part of core in Drupal 7.)
FileField Paths (http://drupal.org/project/filefield_paths)
RequiresCCK, Token, FileField.
Adds node tokens to FileField.
ImageField Tokens (http://drupal.org/project/imagefield_tokens)
Requires CCK, Token, FileField, FileField Paths, ImageField.
Adds node tokens to ImageField's ALT and Title text fields.