Assuming your stub is only used for the home page.

In your stub declare a trigger var with the name of your choice :

$home_page = true; // I'm really unimaginative when it comes to var/function names

Then, in your index.main.php or posts.main.php ... whichever your skin has ... just look for the same var and then display excerpt instead of post content ;)

global $home_page;
if( !empty( $home_page ) )
{ // do the excerpt bit
  echo $Item->get('excerpt');
}
else
{ // do the normal content bit
 $Item->content();
}

*note* free typed so backup your files first ;)

¥
}

Hey, thanks a lot - I see where you're going with this but I'm afraid I might have to get some help getting there with you...

So I have myskin/index.main.php (this is showing at blogs/)
and I have mystub/index.main.php (this is showing in the iframe on the home page)

I've added the helpful-if-not-imaginative variable to the mystub/index.main.php . Then I've added the other code to myskin/index.main.php :
[php]<?php
// --------------------------------- START OF POSTS -------------------------------------
// Display message if no post:
display_if_empty();
global $home_page;
if( !empty( $home_page ) )
{ // do the excerpt bit
echo $Item->get('excerpt');
}
else
{ // do the normal content bit
$Item->content();
}
while( $Item = & mainlist_get_item() )
{ // For each blog post, do everything below up to the closing curly brace "}"
?>[/php]

So my question is - where does excerpt originate and where should the code above be put around the posts in the main /blogs /?

I'm sorry to be so dense, but I do appreciate your help.

Okay I tried to follow this:

http://forums.b2evolution.net/viewtopic.php?t=19044&highlight=excerpt

and I can't see those settings under SEO - what am I missing? thanks to any help