Couldn't you do something simple with hook_nodeapi() where $op = 'view' and add the text you want to the node at that point?

To make that into a module, you would just need to create the admin page, write the submit and validate functions, and then get the data from the database and add it when the node is being viewed.

Just my $.02 worth.

Steve

Vasileios Lourdas wrote: 
Hi,

Is there a module that has functionality similar to contemplate, but instead 
of modifying the teaser/body after the node creation and during the node's 
display, the body textarea is prefilled with the text of my choice? What I 
need to have is when a user visits the node/add page, the body textarea must 
be prefilled with text that has been set somewhere in the administration 
area. For this particular application, this text will be a pair of signatures 
and since there will be a number of nodes using these signatures, I figured 
out that a good solution was to have the body textarea prefilled with the 
appropriate html snippet. It will be the user's preference to keep it or 
delete it.

I hope that makes sense.