Smart Paging

Provides splitting up long Drupal content into sub pages by number of characters/words or by a placeholder HTML tag. 

http://drupal.org/project/smart_paging

Installation

1. Copy the extracted smart_paging directory to your Drupal sites/all/modules directory
2. Login as an administrator. Enable the module at the 
3. Configure Smart Paging 
4. Enable Smart Paging input filter 
5. Disable the "Convert line breaks into HTML (i.e. <br> and <p>)" input filter. In replace to
   this input filter, enable the "Convert line breaks into HTML (i.e. <br> and <p>) for Smart
   Paging compatibility"
6. Verify that the comment tags <!-- --> are included in "Limit allowed HTML tags" list if it
   is enabled in input filter Text formats settings.

Positives:

• URL for sub pages made more SEO friendly and works even for aliased URL path
• The user has more control over Smart Paging configuration. An option is provided at "Manage Display" page of an entity type whether to control Smart Paging display behavior during content editing or at "Manage Display" page itself.
• Weight and visibility of Smart Paging can be controlled at "Manage Display" page of an entity type (bundle).
• Integrated with WYSIWYG

Negatives:

Smart Paging feature can be applied only to CCK fields (with text format) of node, user and taxonomy term entities.

Overall:

One of the first module I've blogged about that had enough options and easy to work.