Node Convert adds a menu tab "Convert" on the node view page, i.e. node/1/convert, which gives the ability of converting the node from its current node type to another node type. Also it gives the ability of transfering all the custom CCK field values of the current node type to the destination CCK fields, or discard them. As of 5.x-1.4 you can bulk convert many nodes of the same type, to another one that can be accesed in Administer → Content → Convert Nodes.

The module has been tested on converting node types with the following CCK fields:

• Text
• Number
• Image
• Node reference
• User reference
• Link
• Date
• Datestamp
• Email
• Audio
• Video

Also supports book and forum nodes.
Note #1: This module requires the CCK module.
Note #2: If you get an Unknown column 'ctid' error when updating to 6.x-1.5, don't worry. Node Convert should still work.

Note #3: Drupal 7 version currently lacks hook_node_convert_change support.